# Charles Sanders Peirce: Wikis

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# Encyclopedia

Charles Sanders Peirce

Charles Sanders Peirce
Born September 10, 1839
Cambridge, Massachusetts
Died April 19, 1914 (aged 74)
Milford, Pennsylvania
Nationality American
Fields Logic, Mathematics,
Statistics, Philosophy,
Metrology, Chemistry
Religious
stance
Episcopal but
unconventional
C. S. Peirce articles
General:  Charles Sanders Peirce
Charles Sanders Peirce bibliography
Philosophical: Categories (Peirce)
Semiotic elements and
classes of signs (Peirce)

Pragmatic maximPragmaticism
SynechismTychism
Classification of the sciences (Peirce)
Biographical:  Juliette Peirce
Charles Santiago Sanders Peirce
Abbreviations
CDPT Commens Dictionary
of Peirce's Terms
CP x.y Collected Papers
volume x, paragraph y
EP x:y The Essential Peirce
volume x, page y
NEM x:y The New Elements of
Mathematics

volume x, page y
W x:y Writings of Charles S. Peirce
volume x, page y.

Charles Sanders Peirce (pronounced /ˈpɜrs/ purse[1]) (September 10, 1839 – April 19, 1914) was an American philosopher, logician, mathematician, and scientist, born in Cambridge, Massachusetts. Peirce was educated as a chemist and employed as a scientist for 30 years. It is largely his contributions to logic, mathematics, philosophy, and semiotics (and his founding of pragmatism) that are appreciated today. In 1934, the philosopher Paul Weiss called Peirce "the most original and versatile of American philosophers and America's greatest logician".[2]

An innovator in many fields — including philosophy of science, epistemology, metaphysics, mathematics, statistics, research methodology, and the design of experiments in astronomy, geophysics, and psychology — Peirce considered himself a logician first and foremost. He made major contributions to logic, but "logic" for him encompassed much of that which is now called epistemology and philosophy of science. He saw logic as the formal branch of semiotics, of which he is a founder. As early as 1886 he saw that logical operations could be carried out by electrical switching circuits, an idea used decades later to produce digital computers.

## Life

Charles Peirce's birthplace near Harvard Yard.

Charles Sanders Peirce was the son of Sarah Hunt Mills and Benjamin Peirce, a professor of astronomy and mathematics at Harvard University, perhaps the first serious research mathematician in America. At 12 years of age, Charles read an older brother's copy of Richard Whately's Elements of Logic, then the leading English language text on the subject. Thus began his lifelong fascination with logic and reasoning. He went on to obtain the BA and MA from Harvard. In 1863 the Lawrence Scientific School awarded him, summa cum laude, its first M.Sc. in chemistry; otherwise his academic record was undistinguished. At Harvard, he began lifelong friendships with Francis Ellingwood Abbot, Chauncey Wright, and William James. One of his Harvard instructors, Charles William Eliot, formed an unfavorable opinion of Peirce. This opinion proved fateful, because Eliot, while President of Harvard 1869–1909—a period encompassing nearly all of Peirce's working life—repeatedly vetoed having Harvard employ Peirce in any capacity.

Peirce suffered from his late teens through the rest of his life from something then known as "facial neuralgia", a very painful nervous/facial condition, which would today be diagnosed as trigeminal neuralgia. The biography by Joseph Brent[3] says that when in the throes of its pain "he was, at first, almost stupefied, and then aloof, cold, depressed, extremely suspicious, impatient of the slightest crossing, and subject to violent outbursts of temper." Its consequences may have led to the social isolation which made his life's later years so tragic.

### United States Coast Survey

Between 1859 and 1891, Peirce was intermittently employed in various scientific capacities by the United States Coast Survey, where he enjoyed the protection of his highly influential father until the latter's death in 1880. This employment exempted Peirce from having to take part in the Civil War. It would have been very awkward for him to do so, as the Boston Brahmin Peirces sympathized with the Confederacy. At the Survey, he worked mainly in geodesy and in gravimetry, refining the use of pendulums to determine small local variations in the strength of Earth's gravity. The Survey sent him to Europe five times, first in 1871, as part of a group dispatched to observe a solar eclipse. While in Europe, he sought out Augustus De Morgan, William Stanley Jevons, and William Kingdon Clifford, British mathematicians and logicians whose turn of mind resembled his own. From 1869 to 1872, he was employed as an Assistant in Harvard's astronomical observatory, doing important work on determining the brightness of stars and the shape of the Milky Way. (On Peirce the astronomer, see Lenzen's chapter in Moore and Robin, 1964.) In 1876 he was elected a member of the National Academy of Sciences. In 1878, he was the first to define the meter as so many wavelengths of light of a certain frequency, the definition employed until 1983 (Taylor 2001: 5)[4].

During the 1880s, Peirce's indifference to bureaucratic detail waxed while the quality and timeliness of his Survey work waned. Peirce took years to write reports that he should have completed in mere months. Meanwhile, he wrote hundreds of logic, philosophy, and science entries for the Century Dictionary.[5] In 1885, an investigation by the Allison Commission exonerated Peirce, but led to the dismissal of Superintendent Julius Hilgard and several other Coast Survey employees for misuse of public funds. In 1891, Peirce resigned from the Coast Survey, at the request of Superintendent Thomas Corwin Mendenhall. He never again held regular employment.

### Johns Hopkins University

In 1879, Peirce was appointed Lecturer in logic at the new Johns Hopkins University. That university was strong in a number of areas that interested him, such as philosophy (Royce and Dewey did their PhDs at Hopkins), psychology (taught by G. Stanley Hall and studied by Joseph Jastrow, who coauthored a landmark empirical study with Peirce), and mathematics (taught by J. J. Sylvester, who came to admire Peirce's work on mathematics and logic). This nontenured position proved to be the only academic appointment Peirce ever held.

Brent documents something Peirce never suspected, namely that his efforts to obtain academic employment, grants, and scientific respectability were repeatedly frustrated by the covert opposition of a major American scientist of the day, Simon Newcomb. Peirce's ability to find academic employment may also have been frustrated by a difficult personality. Brent conjectures about various psychological and other difficulties.

Peirce's personal life also handicapped him. His first wife, Harriet Melusina Fay, left him in 1875. He soon took up with a woman, Juliette, whose maiden name and nationality remain uncertain to this day (the best guess is that her name was Juliette Froissy and that she was French), but his divorce from Harriet became final only in 1883, after which he married Juliette. That year, Newcomb pointed out to a Johns Hopkins trustee that Peirce, while a Hopkins employee, had lived and traveled with a woman to whom he was not married. The ensuing scandal led to his dismissal. Just why Peirce's later applications for academic employment at Clark University, University of Wisconsin–Madison, University of Michigan, Cornell University, Stanford University, and the University of Chicago were all unsuccessful can no longer be determined. Presumably, his having lived with Juliette for years while still legally married to Harriet led him to be deemed morally unfit for academic employment anywhere in the USA. Peirce had no children by either marriage.

### Poverty

Cambridge, where Peirce was born and raised, New York City, where he often visited and sometimes lived, and Milford, where he spent the later years of his life with his second wife Juliette.
Juliette and Charles by the well at their home, Arisbe, in 1907.

In 1887 Peirce spent part of his inheritance from his parents to buy 2,000 acres (8 km2) of rural land near Milford, Pennsylvania, land which never yielded an economic return. There he built a large house which he named "Arisbe" where he spent the rest of his life, writing prolifically, much of it unpublished to this day. His living beyond his means soon led to grave financial and legal difficulties. Peirce spent much of his last two decades unable to afford heat in winter, and subsisting on old bread donated by the local baker. Unable to afford new stationery, he wrote on the verso side of old manuscripts. An outstanding warrant for assault and unpaid debts led to his being a fugitive in New York City for a while. Several people, including his brother James Mills Peirce and his neighbors, relatives of Gifford Pinchot, settled his debts and paid his property taxes and mortgage.

Peirce did some scientific and engineering consulting and wrote a good deal for meager pay, mainly dictionary and encyclopedia entries, and reviews for The Nation (with whose editor, Wendell Phillips Garrison, he became friendly). He did translations for the Smithsonian Institution, at its director Samuel Langley's instigation. Peirce also did substantial mathematical calculations for Langley's research on powered flight. Hoping to make money, Peirce tried inventing. He began but did not complete a number of books. In 1888, President Grover Cleveland appointed him to the Assay Commission. From 1890 onwards, he had a friend and admirer in Judge Francis C. Russell of Chicago, who introduced Peirce to Paul Carus and Edward Hegeler, the editor and the owner, respectively, of the pioneering American philosophy journal The Monist, which eventually published 14 or so articles by Peirce. He applied to the newly formed Carnegie Institution for a grant to write a book summarizing his life's work. The application was doomed; his nemesis Newcomb served on the Institution's executive committee, and its President had been the President of Johns Hopkins at the time of Peirce's dismissal.

The one who did the most to help Peirce in these desperate times was his old friend William James, dedicating his Will to Believe (1897) to Peirce, and arranging for Peirce to be paid to give two series of lectures at or near Harvard (1898 and 1903)[6]. Most important, each year from 1907 until James's death in 1910, James wrote to his friends in the Boston intelligentsia, asking that they contribute financially to help support Peirce; the fund continued even after James's death in 1910. Peirce reciprocated by designating James's eldest son as his heir should Juliette predecease him.[7] It has also been believed that this was why Peirce used "Santiago" ("St. James" in Spanish) as a middle name, but he appeared in print as early as 1890 as Charles Santiago Peirce. (See Charles Santiago Sanders Peirce for discussion and references).

Peirce died destitute in Milford, Pennsylvania, twenty years before his widow.

## Reception

Bertrand Russell (1959) wrote[8], "Beyond doubt [...] he was one of the most original minds of the later nineteenth century, and certainly the greatest American thinker ever." (His Principia Mathematica does not mention Peirce; Peirce's work was not widely known till later.[9]) A. N. Whitehead, while reading some of Peirce's unpublished manuscripts soon after arriving at Harvard in 1924, was struck by how Peirce had anticipated his own "process" thinking. (On Peirce and process metaphysics, see the chapter by Lowe in Moore and Robin, 1964.) Karl Popper viewed Peirce as "one of the greatest philosophers of all times".[10] Yet Peirce's accomplishments were not immediately recognized. His imposing contemporaries William James and Josiah Royce admired him, and Cassius Jackson Keyser at Columbia and C. K. Ogden wrote about Peirce with respect, but to no immediate effect.

The first scholar to give Peirce his considered professional attention was Royce's student Morris Raphael Cohen, the editor of a 1923 anthology of Peirce's writings titled Chance, Love, and Logic and the author of the first bibliography of Peirce's scattered writings. John Dewey had had Peirce as an instructor at Johns Hopkins and, from 1916 onwards, Dewey's writings repeatedly mention Peirce with deference. His 1938 Logic: The Theory of Inquiry is Peircean through and through. The publication of the first six volumes of the Collected Papers (1931–35), the most important event to date in Peirce studies and one that Cohen made possible by raising the needed funds, did not prompt an outpouring of secondary studies. The editors of those volumes, Charles Hartshorne and Paul Weiss, did not become Peirce specialists. Early landmarks of the secondary literature include the monographs by Buchler (1939), Feibleman (1946), and Goudge (1950), the 1941 Ph.D. thesis by Arthur W. Burks (who went on to edit volumes 7 and 8 of the Collected Papers), and the edited volume Wiener and Young (1952). The Charles S. Peirce Society was founded in 1946. Its Transactions, an academic journal specializing in Peirce, pragmatism, and American philosophy, has appeared since 1965.

In 1949, while doing unrelated archival work, the historian of mathematics Carolyn Eisele (1902–2000) chanced on an autograph letter by Peirce. Thus began her 40 years of research on Peirce the mathematician and scientist, culminating in Eisele (1976, 1979, 1985). Beginning around 1960, the philosopher and historian of ideas Max Fisch (1900–1995) emerged as an authority on Peirce; Fisch (1986) reprints many of the relevant articles, including a wide-ranging survey (Fisch 1986: 422-48) of the impact of Peirce's thought through 1983.

Peirce has come to enjoy a significant international following, marked by university research centers devoted to Peirce studies and pragmatism in Brazil[11], Finland[12], Germany[13], France[14], Spain[15], and Italy[16]. His writings have been translated into several languages, including German, French, Finnish, Spanish, and Swedish. Since 1950, there have been French, Italian, Spanish and British Peirceans of note. For many years, the North American philosophy department most devoted to Peirce was the University of Toronto's, thanks in good part to the leadership of Thomas Goudge and David Savan. In recent years, American Peirce scholars have clustered at Indiana University - Purdue University Indianapolis, home of the Peirce Edition Project (PEP), and the Pennsylvania State University.

Robert Burch has commented on Peirce's current influence as follows:

Currently, considerable interest is being taken in Peirce's ideas from outside the arena of academic philosophy. The interest comes from industry, business, technology, and the military; and it has resulted in the existence of a number of agencies, institutes, and laboratories in which ongoing research into and development of Peircean concepts is being undertaken. (Burch 2001/2006[17].)

## Works

Peirce's reputation rests largely on a number of academic papers published in American scientific and scholarly journals such as Proceedings of the American Academy of Arts and Sciences, the Journal of Speculative Philosophy, The Monist, Popular Science Monthly, the American Journal of Mathematics, Memoirs of the National Academy of Sciences, The Nation, and others. The only full-length book (neither extract nor pamphlet) that Peirce authored and saw published in his lifetime was Photometric Researches (1878), a 181-page monograph on the applications of spectrographic methods to astronomy. While at Johns Hopkins, he edited Studies in Logic (1883), containing chapters by himself and his graduate students. Besides lectures during his years (1879–1884) as Lecturer in Logic at Johns Hopkins, he gave at least nine series of lectures, many now published; see Lectures by Peirce.

Harvard University bought from Peirce's widow soon after his death the papers found in his study, but did not microfilm them until 1964. Only after Richard Robin (1967)[18] catalogued this Nachlass did it become clear that Peirce had left approximately 1650 unpublished manuscripts, totaling over 100,000 pages.[19] Most of it remains unpublished, except on microfilm. For more on the vicissitudes of Peirce's papers, see Houser (1989)[20].

List of major articles and lectures

See Charles Sanders Peirce bibliography for extensive list of his works, along with links to many of them readable online.

 On a New List of Categories (Presented 1867, his philosophy's seminal work, see #Theory of categories below.) Questions Concerning Certain Faculties Claimed for Man (1868) Some Consequences of Four Incapacities (1868. Rejects Cartesian foundationalism, see #Presuppositions of logic, below. Also argues that the general is real.) Grounds of Validity of the Laws of Logic: Further Consequences of Four Incapacities (1869) The Harvard lectures on British logicians (1869–70) Description of a Notation for the Logic of Relatives (1870) Note on the Theory of the Economy of Research (1876) Illustrations of the Logic of Science (1877–78) (See #Pragmatism, below.) The Fixation of Belief (1877) How to Make Our Ideas Clear (1878) The Doctrine of Chances (1878) The Probability of Induction (1878) The Order of Nature (1878) Deduction, Induction, and Hypothesis (1878) On the Algebra of Logic (1880) A Theory of Probable Inference. Note A: On a Limited Universe of Marks. Note B: The Logic of Relatives (1883) On Small Differences in Sensation (with Joseph Jastrow, 1884) On the Algebra of Logic: A Contribution to the Philosophy of Notation (presented 1884) A Guess at the Riddle (1887–88 MS) Trichotomic (1888 MS) The Monist Metaphysical Series (1891–93) The Architecture of Theories (1891) The Doctrine of Necessity Examined (1892) The Law of Mind (1892) Man's Glassy Essence (1892) Evolutionary Love (1893) Immortality in the Light of Synechism (1893 MS) The Logic of Relatives (1894) The lectures on "Reasoning and the Logic of Things" in Cambridge, MA (1898, invited by William James) F.R.L. [First Rule of Logic] (1899 MS against barriers to inquiry, see #Presuppositions of logic below) Minute Logic (1901–02 MSS) Application of C. S. Peirce to the Executive Committee of the Carnegie Institution (1902) The Simplest Mathematics (1902 MS) The Harvard lectures on pragmatism (1903) The Lowell lectures and syllabus on topics of logic (1903) Kaina Stoicheia [New Elements] (1904 MS) What Pragmatism Is (1905) Issues of Pragmaticism (1905) Prolegomena To an Apology For Pragmaticism (1906) A Neglected Argument for the Reality of God (1908, outlines much of Peirce's philosophy)

The first published anthology of Peirce's articles was the one-volume Chance, Love and Logic: Philosophical Essays, edited by Morris Raphael Cohen, 1923, still in print. Other one-volume anthologies were published in 1940, 1957, 1958, 1972, and 1994, most still in print. The main posthumous editions of Peirce's works in their long trek to light, often multi-volume, and some still in print, have included:

1931–58: Collected Papers of Charles Sanders Peirce (CP), 8 volumes, includes many published works, along with a selection of previously unpublished work and a smattering of his correspondence. This long-time standard work in Peirce studies is organized thematically, but texts from different times are often stitched together, making for contradictory pieces, requiring frequent visits to editors' notes, and obscuring Peirce's development. Edited (1–6) by Charles Hartshorne and Paul Weiss and (7–8) by Arthur Burks, in print from Harvard and online via InteLex.

1975–87: Charles Sanders Peirce: Contributions to The Nation, 4 volumes, includes Peirce's more than 300 reviews and articles published 1869–1908 in The Nation. Edited by Kenneth Laine Ketner and James Edward Cook, out of print except online via InteLex.

1976: The New Elements of Mathematics by Charles S. Peirce (NEM), 4 volumes in 5, included many previously unpublished Peirce manuscripts on mathematical subjects, along with Peirce's important published mathematical articles. Edited by Carolyn Eisele, out of print.

1977: Semiotic and Significs: The Correspondence between C. S. Peirce and Victoria Lady Welby (2nd edition 2001), included Peirce's entire correspondence (1903–1912) with Victoria, Lady Welby. Peirce's other published correspondence is largely limited to the 14 letters included in volume 8 of the Collected Papers, and the 20-odd pre-1890 items included so far in the Writings. Edited by Charles S. Hardwick with James Cook, out of print.

1981–now: Writings of Charles S. Peirce, A Chronological Edition (W), Volumes 1-6 & 8, of a projected 30. The limited coverage, and defective editing and organization, of the Collected Papers led Max Fisch and others in the 1970s to found the Peirce Edition Project (PEP), whose mission is to prepare a more complete critical chronological edition. Only seven volumes have appeared to date, but they cover the period from 1859–1892, when Peirce carried out much of his best-known work. W 8 was published in November 2009; and work continues on W 7, 9, and 11. In print from Indiana University and (1-6) online via InteLex.

1985: Historical Perspectives on Peirce's Logic of Science: A History of Science, 2 volumes. Auspitz has said[21], "The extent of Peirce's immersion in the science of his day is evident in his reviews in the Nation [...] and in his papers, grant applications, and publishers' prospectuses in the history and practice of science", referring latterly to Historical Perspectives. Edited by Carolyn Eisele, out of print.

1992: Reasoning and the Logic of Things collects in one place Peirce's 1898 series of lectures invited by William James. Edited by Kenneth Laine Ketner, with commentary by Hilary Putnam, in print from Harvard.

1992–98: The Essential Peirce (EP), 2 volumes, is an important recent sampler of Peirce's philosophical writings. Edited (1) by Nathan Hauser and Christian Kloesel and (2) by PEP editors, in print from Indiana University.

1997: Pragmatism as a Principle and Method of Right Thinking collects Peirce's 1903 Harvard "Lectures on Pragmatism" in a study edition, including drafts, of Peirce's lecture manuscripts, which had been previously published in abridged form; the lectures now also appear in EP 2. Edited by Patricia Ann Turisi, in print from SUNY.

## Mathematics

Peirce quincuncial projection

Peirce's most important work in pure mathematics was in logical and foundational areas. He also worked on linear algebra, matrices, various geometries, topology and Listing numbers, Bell numbers, graphs, the four-color problem, and the nature of continuity. He worked not only in pure areas but also on applications for economics, engineering, and map projections (the Peirce quincuncial projection of a sphere keeps angles true and results in less distortion of area than in other projections), and he was especially active in probability and statistics.[22]

Peirce made a number of striking discoveries in foundational mathematics, nearly all of which came to be appreciated only long after he died. He:

 The Peirce arrow ↓ Peirce's symbol for "(neither)...nor...", reflecting negation of "or" (its standard symbol "v" is the arrowhead).

Peirce wrote drafts for an introductory textbook, with the working title The New Elements of Mathematics, that presented mathematics from an original standpoint. Those drafts and many other of his previously unpublished mathematical manuscripts finally appeared[22] in The New Elements of Mathematics by Charles S. Peirce (1976), edited by mathematician Carolyn Eisele.

Peirce regarded mathematics as more basic than philosophy and the special sciences (of nature and mind), but credited this observation to Auguste Comte. Peirce classified mathematics into three subcategories, (1) logic, (2) discrete series, and (3) pseudo-continuous series (as he called them, including the real numbers) and continuous series. Influenced by his father Benjamin, Peirce stated the following propositions about mathematics and logic:

• Mathematics is not just the science of quantity but is more broadly the science which draws necessary conclusions.
• Mathematics studies purely hypothetical objects.
• Mathematics aids logic, not vice versa. (Here, Peirce criticized Dedekind's logicism.)
• Logic itself, which Peirce placed in philosophy, is the science about drawing conclusions necessary and otherwise.[25]

### Mathematics of logic

Beginning with his first paper on the "Logic of Relatives" (1870), Peirce extended the theory of relations that Augustus De Morgan had just recently awakened from its Cinderella slumbers. Much of the mathematics of relations now taken for granted was "borrowed" from Peirce, not always with all due credit (Anellis 1995[9]). In 1918 the logician C. I. Lewis wrote, "The contributions of C.S. Peirce to symbolic logic are more numerous and varied than those of any other writer — at least in the nineteenth century."[26] Beginning in 1940, Alfred Tarski and his students rediscovered aspects of Peirce's larger vision of relational logic, developing the perspective of relational algebra.

Relational logic came to have applications. In mathematics, relational logic influenced the abstract analysis of E. H. Moore and the lattice theory of Garrett Birkhoff. In computer science, the relational model for databases was developed with Peircian ideas in work of Edgar F. Codd, who was a doctoral student of Arthur W. Burks, a Peirce scholar. In economics, relational logic was used by Frank P. Ramsey, John von Neumann, and Paul Samuelson to study preferences and utility and by Kenneth J. Arrow in Social Choice and Individual Values, following Arrow's association with Tarski at City College of New York.

On Peirce and his contemporaries Ernst Schröder and Gottlob Frege, Hilary Putnam (1982)[27] documented that Frege's work on the logic of quantifiers had little influence on his contemporaries, although it was published four years before the work of Peirce and his student Oscar Howard Mitchell. Mathematicians and logicians learned about the logic of quantifiers through the independent work of Peirce and Mitchell, particularly through Peirce's "On the Algebra of Logic: A Contribution to the Philosophy of Notation"[28] (1885), published in the premier American mathematical journal of the day. This article was cited by Peano and Ernst Schröder, among others, who ignored Frege. These researchers also adopted and modified Peirce's notations, which are a typographical variant of those currently used. Peirce apparently was ignorant of Frege's work, despite their mutual interests and overlapping achievements in logic, philosophy of language, and the foundations of mathematics. On how the young Bertrand Russell, especially his Principles of Mathematics and Principia Mathematica, did not do Peirce justice, see Anellis (1995)[9].

Peirce's other major discoveries in formal logic include:

Jean Van Heijenoort (1967)[30], Jaakko Hintikka in his chapter in Brunning and Forster (1997)[31], and Geraldine Brady (2000)[32] divide those who study formal (and natural) languages into two camps: the model-theorists / semanticists, and the proof theorists / universalists. Hintikka and Brady view Peirce as a pioneer model theorist.

A philosophy of logic, grounded in his categories and semiotic, can be extracted from Peirce's writings and, along with Peirce's logical work more generally, is exposited and defended in Hilary Putnam (1982)[27]; the Introduction in Houser et al. (1997)[33]; and Dipert's chapter in Misak (2004)[34].

### Continuity

Continuity and synechism are important, even crucial, in Peirce's philosophy. He worked long on the mathematics of continua, and held for many years that the real numbers constituted a pseudocontinuum and that a true continuum of instants was not a "multitude" (as he called it) or Cantorian aleph, that it had, within any lapse of time, room enough for any multitude howsoever great, and that it was the real subject matter of that which we now call topology.[35] In 1908 he gave up on that particular conception of continua.[36]

### Probability and statistics

Peirce held that science achieves statistical probabilities, not certainties, and that chance, a veering from law, is absolutely real. He assigned probability to an argument’s conclusion rather than to a proposition, event, etc., as such. Most of his statistical writings promote the frequency interpretation of probability (objective ratios of cases), and many of his writings express skepticism about (and criticize the use of) probability when such models are not based on objective randomization.[37] Though Peirce was largely a frequentist, his possible world semantics introduced the "propensity" theory of probability. Peirce (sometimes with Jastrow) investigated the probability judgments of experimental subjects, pioneering decision analysis.

Peirce was one of the founders of statistics. He formulated modern statistics in "Illustrations of the Logic of Science" (1877–8) and "A Theory of Probable Inference" (1883). With a repeated measures design, he introduced blinded, controlled randomized experiments (before Ronald A. Fisher). He invented optimal design for experiments on gravity, in which he "corrected the means". He used logistic regression, correlation, and smoothing. Peirce extended the work on outliers by Benjamin Peirce, his father. He introduced terms "confidence" and "likelihood" (before Jerzy Neyman and Fisher). (See Stephen Stigler's historical books and Ian Hacking 1990:200–201.)

## Philosophy

It is not sufficiently recognized that Peirce’s career was that of a scientist, not a philosopher; and that during his lifetime he was known and valued chiefly as a scientist, only secondarily as a logician, and scarcely at all as a philosopher. Even his work in philosophy and logic will not be understood until this fact becomes a standing premise of Peircean studies. (Max Fisch, in Fisch, Moore, and Robin 1964, 486).

Peirce was a working scientist for 30 years, and arguably was a professional philosopher only during the five years he lectured at Johns Hopkins. He learned philosophy mainly by reading, each day, a few pages of Kant's Critique of Pure Reason, in the original German, while a Harvard undergraduate. His writings bear on a wide array of disciplines, including astronomy, metrology, geodesy, mathematics, logic, philosophy, the history and philosophy of science, statistics, linguistics, economics, and psychology. This work has enjoyed renewed interest and approval, a revival inspired not only by his anticipations of recent scientific developments but also by his demonstration of how philosophy can be applied effectively to human problems.

Peirce's philosophy includes a pervasive three-category system, fallibilism, critical common-sensism (fallibilistic but not radically skeptical), logic as formal semiotic, philosophical pragmatism, which he founded, Scholastic realism, theism, objective idealism, and belief in the reality of continuity and of chance, mechanical necessity, and evolutionary love. In his work, fallibilism and pragmatism may be seen as playing roles somewhat similar to those of skepticism and positivism, respectively, in others' work. However, for Peirce, fallibilism is a basis for belief in the reality of chance and continuity, and pragmatism fortifies belief in the reality of the general.

For Peirce, First Philosophy, which he also called cenoscopy, is less basic than mathematics and more basic than the special sciences (of nature and mind); it studies positive phenomena in general, phenomena available to any person at any waking moment, and does not seek novel phenomena or resort to special experiences or experiments in order to settle its questions.[38] He divided such philosophy into (1) phenomenology (which he also called phaneroscopy or categorics), (2) normative sciences (esthetics, ethics, and logic), and (3) metaphysics; his views on them are discussed in order below.

### Theory of categories

On May 14, 1867, the 27-year-old Peirce presented a paper entitled "On a New List of Categories" to the American Academy of Arts and Sciences, which published it the following year. The paper outlined a theory of predication, involving three universal categories which Peirce developed in reaction to his reading of Aristotle, Kant, and Hegel, categories which Peirce would apply throughout philosophy and elsewhere for the rest of his life. Most students of Peirce will readily agree about their prevalence throughout his philosophical work. Peirce scholars generally regard the "New List" as foundational or breaking the ground for Peirce's "architectonic", his blueprint for a pragmatic philosophy. In the categories one will discern, concentrated, the pattern which one finds formed by the three grades of clearness in "How To Make Our Ideas Clear" (1878 foundational paper for pragmatism), and in numerous other trichotomies in his work.

"On a New List of Categories" is cast as a Kantian deduction; it is short but dense and difficult to summarize. The following table is compiled from that and later works.

Peirce's Categories (technical name: the cenopythagorean categories[39])
Name: Typical characterizaton: As universe of experience: As quantity: Technical definition: Valence, "adicity":
Firstness. Quality of feeling. Ideas, chance, possibility. Vagueness, "some". Reference to a ground (a ground is a pure abstraction of a quality).[40] Essentially monadic (the quale, in the sense of the such,[41] which has the quality).
Secondness. Reaction, resistance, (dyadic) relation. Brute facts, actuality. Singularity, discreteness, “this”. Reference to a correlate (by its relate). Essentially dyadic (the relate and the correlate).
Thirdness. Representation, mediation. Habits, laws, necessity. Generality, continuity, "all". Reference to an interpretant*. Essentially triadic (sign, object, interpretant*).

*Note: An interpretant is an interpretation in the sense of the product of an interpretive process or the content of an interpretation.

### Esthetics and ethics

Peirce did not write extensively in esthetics and ethics, but held that, together with logic in the broad sense, those studies constituted the normative sciences. He defined esthetics as the study of good and bad; and characterized the good as "the admirable". He held that, as the study of good and bad, esthetics is the study of the ends governing all conduct and comes ahead of other normative studies.[42]

Peirce reserved the spelling "aesthetics" for the study of artistic beauty.

## Philosophy: Logic, or semiotic

Semiotics
General concepts
Methods
Semioticians
Related topics

### Logic as philosophical

Peirce regarded logic per se as a division of philosophy, as a normative science after esthetics and ethics, as more basic than metaphysics[43], and as "the art of devising methods of research"[44]. More generally, as inference, "logic is rooted in the social principle", since inference depends on a standpoint that, in a sense, is unlimited[45]. Peirce called (with no sense of deprecation) "mathematics of logic" much of the kind of thing which, in current research and applications, is called simply "logic". He was productive in both (philosophical) logic and logic's mathematics, which were connected deeply in his work and thought.

Peirce argued that logic is formal semiotic[46], the formal study of signs in the broadest sense, not only signs that are artificial, linguistic, or symbolic, but also signs that are semblances or are indexical such as reactions. Peirce held that "all this universe is perfused with signs, if it is not composed exclusively of signs"[47], along with their representational and inferential relations. He argued that, since all thought takes time, all thought is in signs[48] and sign processes ("semiosis") such as the inquiry process. He divided logic into: (1) speculative grammar, or stechiology, on how signs can signify and, in relation to that, what kinds of signs there are, how they combine, and how some embody or incorporate others; (2) logical critic, or logic proper, on the modes of inference; and (3) speculative rhetoric, or methodeutic, the philosophical theory of inquiry, including pragmatism.

#### Presuppositions of logic

In his "F.R.L." [First Rule of Logic] (1899), Peirce states that the first, and "in one sense, this sole", rule of reason is that, in order to learn, one needs to desire to learn and desire it without resting satisfied with that which one is inclined to think.[43] So, the first rule is, to wonder. Peirce proceeds to a critical theme in the shaping of theories, not to mention associated practices:

...there follows one corollary which itself deserves to be inscribed upon every wall of the city of philosophy:
Do not block the way of inquiry.

Peirce adds, that method and economy are best in research but no outright sin inheres in trying any theory in the sense that the investigation via its trial adoption can proceed unimpeded and undiscouraged, and that "the one unpardonable offence" is a philosophical barricade against truth's advance, an offense to which "metaphysicians in all ages have shown themselves the most addicted". Peirce in many writings holds that logic precedes metaphysics (ontological, religious, and physical).[49]

Peirce goes on to list four common barriers to inquiry: (1) Assertion of absolute certainty; (2) maintaining that something is absolutely unknowable; (3) maintaining that something is absolutely inexplicable because absolutely basic or ultimate; (4) holding that perfect exactitude is possible, especially such as to quite preclude unusual and anomalous phenomena. To refuse absolute certainty is the heart of fallibilism, which Peirce unfolds into refusals to set up any of the listed barriers. Peirce elsewhere argues (1897) that logic's presupposition of fallibilism leads at length to the view that chance and continuity are very real (tychism and synechism).[50]

One might have thought that, as a whole, the topic belongs within theory of inquiry ("Methodeutic" or "Philosophical or Speculative Rhetoric"), his third department of logic; but the First Rule of Logic pertains to the mind's presuppositions in undertaking reason and logic, presuppositions, for instance, that there are truth and real things independent of what you or I think of them (see below). He describes such ideas as, collectively, hopes which, in particular cases, one is unable seriously to doubt.[51] Peirce argues that it is idle or counterproductive to start philosophy from paper doubts, make-believe doubts, so he rejects Cartesian foundationalism; and Peirce argues that one cannot conceive of the absolutely incognizable, so he rejects the conception (usually ascribed to Kant) of the unknowable thing-in-itself.[52] Those rejections grew into that which he called critical common-sensism, which he regarded as a prerequisite for pragmatism.[53]. It involves the idea that only genuine doubt can power genuine inquiry. It is a kind of combination of (1) Thomas Reid's common-sense philosophy, which resists purging philosophy for the sake of hyperbolic doubts, with (2) a fallibilism which recognizes that even beliefs which we do not now doubt in our hearts may eventually come into sincere question.

#### Logic as formal semiotic

Every mind which passes from doubt to belief must have ideas which follow after one another in time. Every mind which reasons must have ideas which not only follow after others but are caused by them. Every mind which is capable of logical criticism of its inferences, must be aware of this determination of its ideas by previous ideas. (Peirce, "On Time and Thought", W 3:68–69.)

Peirce sought, through his wide-ranging studies through the decades, formal philosophical ways to articulate thought's processes, and also to explain the workings of science. These inextricably entangled questions of a dynamics of inquiry involving nature and nurture led him to develop a theory of signs (semiotic) with very broadened conceptions of signs and inference, and, as its culmination, a theory of inquiry for the task of saying 'how science works' and devising research methods. This would be logic by the medieval definition taught for ages: art of arts, science of sciences, having the way to the principles of all other sciences' methods[44]. Influences radiate from points on parallel lines of inquiry in Aristotle's work, in such loci as:

• The differentiation of the genus of reasoning into three species of inference that are commonly translated into English as abduction, deduction, and induction, in the Prior Analytics, as well as reasoning by analogy (called paradeigma by Aristotle), which Peirce understood in terms of abductive and inductive inference.

Inquiry is a special form of inference process, a specially conducted manner of thinking. Philosophers of the pragmatic school hold with Peirce that "all thought is in signs",[48] where 'sign' is the word for the broadest conceivable variety of semblances, indices, symptoms, signals, symbols, formulas, texts, and so on up the line, that might be imagined. Even intellectual concepts and mental ideas are held to be a special class of signs, corresponding to internal states of the thinking agent that result both in and from the interpretation of external signs.

The subsumption of inquiry within inference in general and the inclusion of thinking within the class of sign processes let us approach the subject of inquiry from two different perspectives:

• The syllogistic approach treats inquiry as a species of logical process, and is limited to those of its aspects that can be related to the most basic laws of inference.
• The sign-theoretic approach views inquiry as a genus of semiosis, an activity taking place within the more general setting of sign relations.

Peirce's semiotic is philosophical logic studied in terms of signs and sign processes. Often using examples from common experience, Peirce defines and discusses things like assertions and interpretations in terms of philosophical logic rather than of psychology, linguistics, or social studies. In a formal vein, Peirce says:

On the Definition of Logic. Logic is formal semiotic. A sign is something, A, which brings something, B, its interpretant sign, determined or created by it, into the same sort of correspondence (or a lower implied sort) with something, C, its object, as that in which itself stands to C. This definition no more involves any reference to human thought than does the definition of a line as the place within which a particle lies during a lapse of time. It is from this definition that I deduce the principles of logic by mathematical reasoning, and by mathematical reasoning that, I aver, will support criticism of Weierstrassian severity, and that is perfectly evident. The word "formal" in the definition is also defined. (Peirce, "Carnegie Application", NEM 4:54).

Peirce called his general study of signs semiotic or semeiotic. Both terms are current in both singular and plural forms.[54] Peirce began writing on semiotic in the 1860s, around the time that he devised his system of three categories. From the beginning he based his semiotic on the understanding of a triadic sign relation. His 1907 definition of semiosis is "action, or influence, which is, or involves, a cooperation of three subjects, such as a sign, its object, and its interpretant, this tri-relative influence not being in any way resolvable into actions between pairs".[55]

### Signs

#### Sign relation

Anything is a sign — not absolutely as itself, but instead in some relation or other. The sign relation is the key. It defines three roles encompassing (1) the sign, (2) the sign's subject matter, called its object, and (3) the sign's meaning or ramification as formed into a kind of effect called its interpretant (a further sign, for example a translation). It is an irreducible triadic relation, according to Peirce. The roles are distinct even when the things that fill those roles are not. The roles are but three; a sign of an object leads to one or more interpretants, and, as signs, they lead to further interpretants.

Extension × intension = information. Two traditional approaches to sign relation, necessary though insufficient, are the way of extension (a sign's objects, also called breadth, denotation, or application) and the way of intension (the objects' characteristics, qualities, attributes referenced by the sign, also called depth, comprehension, significance, or connotation). Peirce adds a third, the way of information, including change of information, in order to integrate the other two approaches into a unified whole.[56] For example, because of the equation above, if a term's total amount of information stays the same, then the more that the term 'intends' or signifies about objects, the fewer are the objects to which the term 'extends' or applies. A proposition's comprehension consists in its implications[57].

Determination. A sign depends on its object in such a way as to represent its object — the object enables and, in a sense, determines the sign. A physically causal sense of this stands out especially when a sign consists in an indicative reaction. The interpretant depends likewise on both the sign and the object — the object determines the sign to determine the interpretant. But this determination is not a succession of dyadic events, like a row of toppling dominoes; sign determination is triadic. For example, an interpretant does not merely represent something which represented an object; instead an interpretant represents something as a sign representing an object. It is an informational kind of determination, a rendering of something more determinately representative.[58] Peirce used the word "determine" not in strictly deterministic sense, but in a sense of "specializes," bestimmt[58], involving variation in measure, like an influence. Peirce came to define sign, object, and interpretant by their (triadic) mode of determination, not by the idea of representation, since that is part of what is being defined.[59] The object determines the sign to determine another sign — the interpretant — to be related to the object as the sign is related to the object, hence the interpretant, fulfilling its function as sign of the object, determines a further interpretant sign. The process is logically structured to perpetuate itself, and is definitive of sign, object, and interpretant in general.[60]

#### Semiotic elements

Peirce held there are exactly three basic elements in semiosis (sign action):

1. A sign (or representamen[61]) represents, in the broadest possible sense of "represents". It is something interpretable as saying something about something. It is not necessarily symbolic, linguistic, or artificial.
2. An object (or semiotic object) is a subject matter of a sign and an interpretant. It can be anything discussable or thinkable, a thing, event, relationship, quality, law, argument, etc., and can even be fictional, for instance Hamlet.[62] All of those are special or partial objects. The object most accurately is the universe of discourse to which the partial or special object belongs.[63] For instance, a perturbation of Pluto's orbit is a sign about Pluto but ultimately not only about Pluto.
3. An interpretant (or interpretant sign) is the sign's more or less clarified meaning or ramification, a kind of form or idea of the difference which the sign's being true or undeceptive would make. (Peirce's sign theory concerns meaning in the broadest sense, including logical implication, not just the meanings of words as properly clarified by a dictionary.) The interpretant is a sign (a) of the object and (b) of the interpretant's "predecessor" (the interpreted sign) as being a sign of the same object. The interpretant is an interpretation in the sense of a product of an interpretive process or a content in which an interpretive relation culminates, though this product or content may itself be an act, a state of agitation, a conduct, etc. As Peirce sometimes put it (he defined sign at least 76 times[60]), the sign stands for the object to the interpretant.

Some of the understanding needed by the mind depends on familiarity with the object. In order to know what a given sign denotes, the mind needs some experience of that sign's object, experience outside of, and collateral to, that sign or sign system. In that context Peirce speaks of collateral experience, collateral observation, collateral acquaintance, all in much the same terms.[64]

#### Classes of signs

Among Peirce's many sign typologies, three stand out, interlocked. They depend respectively on (I) the sign itself, (II) how the sign stands for its denoted object, and (III) how the sign stands for its object to its interpretant. Additionally, each of the three typologies is a three-way division, a trichotomy, via Peirce's three phenomenological categories: (1) quality of feeling, (2) reaction, resistance, and (3) representation, mediation.

I. Qualisign, sinsign, legisign (also called tone, token, type, and also called potisign, actisign, famisign): This typology classifies every sign in terms of the phenomenological category which the sign itself embodies—the qualisign is a quality, a possibility, a "First"; the sinsign is a reaction or resistance, a singular object, an actual event or fact, a "Second"; and the legisign is a habit, a rule, a representational relation, a "Third".

II. Icon, index, symbol: This typology, the best known one, classifies every sign by the category of the sign's way of denoting its object—the icon (also called semblance or likeness) by a quality of its own, the index by factual connection to its object, and the symbol by a habit or rule for its interpretant.

III. Rheme, dicisign, argument (also called sumisign, dicisign, suadisign, also seme, pheme, delome, and regarded as very broadened versions of the traditional term, proposition, argument): This typology classifies every sign by the category which the interpretant attributes to the sign's way of referring to its object—the rheme, for example a term, is a sign interpreted to represent its object in respect of quality; the dicisign, for example a proposition, is a sign interpreted to represent its object in respect of fact; and the argument is a sign interpreted to represent its object in respect of habit or law. This is the culminating typology of the three, where the sign is understood as a structural element of inference.

Every sign falls under one class or another within (I) and within (II) and within (III). Thus each of the three typologies is a three-valued parameter for every sign. The three parameters are not independent of each other; many co-classifications aren't found, for reasons pertaining to the lack of either habit-taking or singular reaction in a quality, and the lack of habit-taking in a singular reaction. The result is not 27 but instead ten classes of signs fully specified at this level of analysis.

### Modes of inference

Borrowing a brace of concepts from Aristotle, Peirce examined three basic modes of reasoning that play roles in inquiry, processes currently known as abductive, deductive, and inductive inference. Peirce also called abduction "retroduction" and, earliest of all, "hypothesis". He characterized it as guessing and as inference to the best explanation. Peirce sometimes expounded the modes of inference by transformations of the classical Barbara (AAA) syllogism, for example in "Deduction, Induction, and Hypothesis" (1878, see CP 2:623). He does this by rearranging the rule (which serves as deduction's major premiss), the case (deduction's minor premiss), and the result (deduction's conclusion):

 Deduction. Rule: All the beans from this bag are white. Case: These beans are from this bag. $\therefore$ Result: These beans are white. Induction. Case: These beans are [randomly selected] from this bag. Result: These beans are white. $\therefore$ Rule: All the beans from this bag are white. Hypothesis (Abduction). Rule: All the beans from this bag are white. Result: These beans are white. $\therefore$ Case: These beans are from this bag.

Peirce 1883 in "A Theory of Probable Inference" (Studies in Logic) equated hypothetical inference with the induction of characters of objects (as he had done in effect before[52]). Eventually dissatisfied, by 1900 he distinguished them once and for all and also wrote that he now took the syllogistic forms and the doctrine of logical extension and comprehension as being less basic than he had thought. In 1903 he presented the following logical form for abductive inference:[65]

The surprising fact, C, is observed;

But if A were true, C would be a matter of course,
Hence, there is reason to suspect that A is true.

Note that the logical form does not also cover induction, since induction does not depend on surprise and does not propose a new idea for its conclusion. Induction seeks facts to test a hypothesis; abduction seeks a hypothesis to account for facts. Peirce now regarded abduction as essentially an initiative toward further inference and study. In his methodeutic or theory of inquiry (see below), Peirce regards the three modes as clarified by their coordination in essential roles in inquiry and science, with abduction generating a possible hypothesis to account for a surprising phenomenon, deduction clarifying the relevant necessary predictive consequences of the hypothesis, and induction testing the predictions against the data to show something actually in operation.[66]

### Pragmatism

Peirce's recipe for pragmatic thinking, which he called pragmatism and, later, pragmaticism, is recapitulated in several versions of the so-called pragmatic maxim. Here is one of his more emphatic reiterations of it:

Consider what effects that might conceivably have practical bearings you conceive the objects of your conception to have. Then, your conception of those effects is the whole of your conception of the object.

William James, among others, regarded two of Peirce's papers, "The Fixation of Belief" (1877) and "How to Make Our Ideas Clear" (1878) as pragmatism's origin. Peirce differed from James and the early John Dewey, in some of their tangential enthusiasms, in being decidedly more rationalistic and realistic, in several senses of those terms, throughout the preponderance of his own philosophical moods. In 1905 Peirce announced his coinage "pragmaticism" and said that the word "pragmatism" was taking on a vulgar literary sense (today "pragmatism" outside of philosophy often connotes compromise or abandonment of aims or principles). Peirce gave another reason in a surviving draft letter c. 1905, saying that "pragmaticism" should be used to single his pragmatism out from its affiliation with those of "Schiller, James, Dewey, Royce, and the rest of us". The question of the relationship between the two reasons has occasioned some controversy.[67]

Pragmatism begins with the idea that belief is that on which one is prepared to act. Peirce's pragmatism is about conceptions of objects and is a method of clarification. It equates any conception's meaning with conceptions of its object's conceivable effects on practice. It is a method of sorting out conceptual confusions occasioned, for example, by distinctions that make (sometimes needed) formal yet not practical differences. Peirce (CP 5.11-12), like James[68] saw pragmatism as embodying familiar attitudes, in philosophy and elsewhere, elaborated into a new deliberate method of thinking and resolving dilemmas.

In "How to Make Our Ideas Clear", Peirce discusses three grades of clearness of conception:

1. Clearness of a conception familiar and readily used, even if unanalyzed and undeveloped.
2. Clearness as of a definition's parts, in virtue of which logicians called a term or idea "distinct", that is, clarified by analysis of just what makes it applicable. Elsewhere, echoing Kant, Peirce calls such a definition "nominal" (CP 5.553).
3. Clearness in virtue of clearness of conceivable practical consequences of the object as conceived of, such as can lead to fruitful reasoning, especially on difficult problems. Here he introduces that which he later called the Pragmatic Maxim.

By way of example of how to clarify conceptions, he addresses conceptions about truth and the real as questions of the presuppositions of reasoning in general. In clearness's second grade (the "nominal" grade), he defines truth as a sign's correspondence to its object, and the real as the object of such correspondence, such that truth and the real are independent of that which you or I or any actual, definite community of inquirers think. After that needful but confined step, next in clearness's third grade (the pragmatic, practice-oriented grade) he defines truth as that which would be reached, sooner or later but still inevitably, by research adequately prolonged, such that the real does depend on that ideal final opinion—a dependence to which he appeals in theoretical arguments elsewhere, for instance for the long-run validity of the rule of induction.[69] Peirce argues that even to argue against the independence and discoverability of truth and the real is to presuppose that there is, about that very question under argument, a truth with just such independence and discoverability.

Peirce also said more specifically, for example, that a conception's meaning consists in "all general modes of rational conduct" implied by "acceptance" of the conception—that is, if one were to accept, first of all, the conception as true, then what could one conceive to be consequent general modes of rational conduct by all who accept the conception as true?—the whole of such consequent general modes is the whole meaning. His pragmatism does not equate a conception's meaning, its intellectual purport, with the conceived benefit or cost of the conception itself, like a meme (or, say, propaganda), outside the perspective of its being true, nor, since a conception is general, is its meaning equated with any definite set of actual consequences or upshots corroborating or undermining the conception or its worth. His pragmatism also bears no resemblance to "vulgar" pragmatism, which misleadingly connotes a ruthless and Machiavellian search for mercenary or political advantage.[67] Rather, Peirce's pragmatic maxim is the heart of his pragmatism as a method of experimentational mental reflection[70] arriving at conceptions in terms of conceivable confirmatory and disconfirmatory circumstances—a method hospitable to the generation of explanatory hypotheses, and conducive to the employment and improvement of verification[71] to test the truth of putative knowledge.

Peirce's pragmatism, as method and theory of definitions and the clearness of ideas, is a department within his theory of inquiry,[72] which he variously called "Methodeutic" and "Philosophical or Speculative Rhetoric". He applied his pragmatism as a method throughout his work.

#### Theory of inquiry

As a method conducive to explanatory hypotheses as well as predictions and testing, pragmatism leads beyond the usual duo of foundational alternatives, namely:

His approach is distinct from foundationalism, empiricist or otherwise, as well as from coherentism, by the following three dimensions:

• Active process of theory generation, with no prior assurance of truth;
• Subsequent application of the contingent theory, aimed toward developing its logical and practical consequences;
• Evaluation of the provisional theory's utility for the anticipation of future experience, and that in dual senses of the word: prediction and control. Peirce's identification of these three dimensions serves to flesh out an approach to inquiry far more solid than the standard image of simple inductive generalization as describing a pattern observed in phenomena. Peirce's pragmatism was the first time the scientific method was proposed as an epistemology for philosophical questions.

A theory that proves itself more successful than its rivals in predicting and controlling our world is said to be nearer the truth. This is an operational notion of truth employed by scientists.

In The Fixation of Belief (1877), Peirce characterized inquiry not as the pursuit of truth but more generally as the struggle to settle irritating doubts, and outlined four methods, graded by their success at it:

1. The method of tenacity (sticking with that which one is inclined to think), which leads to irreconcilable disagreements.
2. The method of authority, which overcomes disagreements but sometimes brutally.
3. The method of congruity or the a priori or the dilettante or "what is agreeable to reason", which promotes conformity less brutally but leads to sterile argumentation and, like the others, gets finally nowhere.
4. The method of science, the method wherein inquiry can, by its own lights, go wrong (fallibilism) and actually tests itself and criticizes, corrects, and improves itself.

Peirce held that, in practical affairs, slow and stumbling ratiocination is often dangerously inferior to instinct, sentiment, and tradition, and that the scientific method is best suited to theoretical research,[73] which in turn should not be bound to the other methods and to practical ends. What recommends scientific method above others finally is that it is deliberately designed to arrive, eventually, at the most secure beliefs, upon which the most successful actions can eventually be based. Starting from the idea that people seek not truth per se but instead to subdue doubt's irritation, Peirce shows how this can lead some to submit to truth.

Peirce extracted the pragmatic model or theory of inquiry from its raw materials in classical logic and refined it in parallel with the early development of symbolic logic to address problems about the nature of scientific reasoning.

Abduction, deduction, and induction do not make complete sense in isolation from each other but comprise a cycle understandable as a whole insofar as they collaborate toward the end of inquiry. In the pragmatic way of thinking in terms of conceivable practical consequences, every thing has a purpose, and a thing's purpose is the first thing that we should try to note about it. Inquiry's purpose is to reduce doubt and lead to a state of belief, which a person in that state will usually call 'knowledge' or 'certainty'. The three kinds of inference function systematically to reduce the uncertainties and difficulties that occasioned the inquiry, and thus, to the extent that inquiry succeeds, lead to an increase in the knowledge or skills, in other words an augmentation in the competence or performance of the agent or community engaged in the inquiry.

For instance, abduction guesses toward best or most-simplifying explanations in order that deduction can explicate them into implied consequences that induction can evaluate in tests. This constrains abduction to produce testable hypotheses, testable in thought, practice, or science (as the case may warrant), since it is not just any guess at explanation that submits itself to reason and bows out when defeated in a match with reality. Likewise, each of the other modes of inference realizes its purpose only in accord with its proper role in the whole cycle of inquiry. No matter how necessary it may be to study these processes in abstraction from each other, the integrity of inquiry places strong limitations on the effective modularity of its principal components.

The question, 'What sort of constraint, exactly, does pragmatic thinking of the end of inquiry place on our guesses?', is generally recognized as the problem of 'giving a rule to abduction'. Peirce's overall answer was the pragmatic maxim. In 1903 Peirce called the question of pragmatism "the question of the logic of abduction".[74]

Peirce outlined the scientific method as follows:[75]

1. Abduction (or retroduction). Guessing, generation of explanatory hypothesis. From abduction, Peirce distinguishes induction as inferring, on the basis of tests, the proportion of truth in the hypothesis. Every inquiry, whether into ideas, brute facts, or norms and laws, arises in the effort to resolve the wonder of surprising observations in the given realm or realms (for example at any stage of an inquiry already underway). All explanatory content of theories is reached by way of abduction, the most insecure among modes of inference. Abduction has general inductive justification in that it works often enough and that nothing else works[76], at least not quickly enough when science is already properly rather slow, the work of indefinitely many generations. One can hope to discover only that which time would reveal sooner or later anyway, so, to expedite this, the economics of research demands and even governs abduction[77], whose modicum of success, excelling that of sheer luck, depends on one's being somehow attuned to nature by instincts developed and likely inborn. Given the reliance on such instinct and the aim at economy, abduction's explanatory hypotheses should have a simplicity optimal in terms of the "facile and natural" (for which Peirce cites Galileo and which Peirce distinguishes from "logical simplicity"[78]). Given that abduction is insecure guesswork, it should imply consequences with conceivable practical bearing leading at least to mental tests, and, in science, lending themselves to scientific testing.

2. Deduction. Analysis of hypothesis and deduction of its consequences in order to test the hypothesis. Two stages:

i. Explication. Logical analysis of the hypothesis in order to render it as distinct as possible.
ii. Demonstration (or deductive argumentation). Deduction of hypothesis's consequence. Corollarial or, if needed, Theorematic.

3. Induction. The long-run validity of the rule of induction is deducible from the principle (presuppositional to reasoning in general) that the real "is only the object of the final opinion to which sufficient investigation would lead".[69] In other words, if there were something to which an inductive process involving ongoing tests or observations would never lead, then that thing would not be real. Three stages:

i. Classification. Classing objects of experience under general ideas.
ii. Probation (or direct Inductive Argumentation): Crude (the enumeration of instances) or Gradual (new estimate of proportion of truth in the hypothesis after each test). Gradual Induction is Qualitative or Quantitative; if Quantitative, then dependent on measurements, or on statistics, or on countings.
iii. Sentential Induction. "...which, by Inductive reasonings, appraises the different Probations singly, then their combinations, then makes self-appraisal of these very appraisals themselves, and passes final judgment on the whole result".[75]

## Philosophy: Metaphysics

Peirce divided metaphysics into (1) ontology or general metaphysics, (2) religious metaphysics, and (3) physical metaphysics.

Ontology. Peirce was a Scholastic Realist, declaring for the reality of generals as early as 1868[79]. Regarding modalities (possibility, necessity, etc.), he came in later years to regard himself as having wavered earlier as to just how positively real the modalities are. In his 1897 "The Logic of Relatives" he wrote:

I formerly defined the possible as that which in a given state of information (real or feigned) we do not know not to be true. But this definition today seems to me only a twisted phrase which, by means of two negatives, conceals an anacoluthon. We know in advance of experience that certain things are not true, because we see they are impossible.

Peirce retained, as useful for some purposes, the definitions in terms of information states, but insisted that the pragmaticist is committed to a strong modal realism by conceiving of objects in terms of predictive general conditional propositions about how they would behave under certain circumstances.[80]

Religious Metaphysics. Peirce believed in God, and characterized such belief as founded in an instinct explorable in musing over the worlds of ideas, brute facts, and evolving norms — and it is a belief in God not as an actual or existent being (in Peirce's sense of those words), but all the same as a real being.[81] In "A Neglected Argument for the Reality of God" (1908),[75] Peirce sketches, for God's reality, an argument to a hypothesis of God as the Necessary Being, a hypothesis which he describes in terms of how it would tend to develop and become compelling in musement and inquiry by a normal person who is led, by the hypothesis, to consider as being purposed the features of the worlds of ideas, brute facts, and evolving norms, such that the thought of such purposefulness will "stand or fall with the hypothesis"; meanwhile, according to Peirce, the hypothesis, in supposing an "infinitely incomprehensible" being, starts off at odds with its own nature as a purportively true conception, and so, no matter how much the hypothesis grows, it both (A) inevitably regards itself as partly true, partly vague, and as continuing to define itself without limit, and (B) inevitably has God appearing likewise vague but growing, though God as the Necessary Being is not vague or growing; but the hypothesis will hold it to be more false to say the opposite, that God is purposeless.

Physical Metaphysics. Peirce held the view, which he called objective idealism, that "matter is effete mind, inveterate habits becoming physical laws".[82] Peirce asserted the reality of (1) chance (his tychist view), (2) mechanical necessity (anancist view), and (3) that which he called the law of love (agapist view). They embody his categories Firstness, Secondness, and Thirdness, respectively. He held that fortuitous variation (which he also called "sporting"), mechanical necessity, and creative love are the three modes of evolution (modes called "tychasm", "anancasm", and "agapasm"[83]) of the universe and its parts. He found his conception of agapasm embodied in Lamarckian evolution; the overall idea in any case is that of evolution tending toward an end or goal, and it could also be the evolution of a mind or a society; it is the kind of evolution which manifests workings of mind in some general sense. He said that overall he was a synechist, holding with reality of continuity[84], especially of space, time, and law[85].

## Science of review

Peirce outlined two fields, "Cenoscopy" and "Science of Review", both of which could be called "philosophy". Both included philosophy about science. In 1903 he arranged them, from more to less theoretically basic, thus:

1. Science of Discovery.
1. Mathematics.
2. Cenoscopy (philosophy as discussed earlier in this article—categorial, normative, metaphysical), as First Philosophy, concerns positive phenomena in general, does not rely on findings from special sciences, and includes the general study of inquiry and scientific method.
3. Idioscopy, or the Special Sciences (of nature and mind).
2. Science of Review, as Ultimate Philosophy, arranges "...the results of discovery, beginning with digests, and going on to endeavor to form a philosophy of science". His examples included Humboldt's Cosmos, Comte's Philosophie positive, and Spencer's Synthetic Philosophy.[86]
3. Practical Science, or the Arts.

Peirce placed, within Science of Review, the work and theory of classifying the sciences (including mathematics and philosophy). His classifications, on which he worked for many years, draw on argument and wide knowledge, and are of interest both as a map for navigating his philosophy and as an accomplished polymath's survey of research in his time.

Contemporaries associated with Peirce

## Notes

1. ^ "Peirce", in the case of C.S. Peirce, always rhymes with the English-language word "terse" and so, in most dialects, is pronounced exactly like the English-language word "purse": Audio (US) . See "Note on the Pronunciation of 'Peirce'", The Peirce [Edition] Project Newsletter, Vol. 1, Nos. 3/4, Dec. 1994, Eprint.
2. ^ Weiss, Paul (1934), "Peirce, Charles Sanders" in the Dictionary of American Biography. Arisbe Eprint.
3. ^ Brent, Joseph (1998), Charles Sanders Peirce: A Life. Revised and enlarged edition, Indiana University Press, Bloomington, IN.
4. ^ Taylor, Barry N., ed. (2001), The International System of Units, NIST Special Publication 330. Washington DC: Superintendent of Documents.
5. ^ See the Peirce Edition Project (PEP) on Peirce's contributions to the Century Dictionary at UQÀM (Université du Québec à Montréal) at http://www.pep.uqam.ca/index_en.pep .
The Century Dictionary itself is available both online (at no charge) and on CD at http://www.global-language.com/century/ .
6. ^ See pp. 261-4, 290-2, & 324 in Brent, Joseph, Charles Sanders Peirce: A Life, 2nd ed. 1998.
7. ^ See pp. 306-7 & 315-6 in Brent, Joseph, Charles Sanders Peirce: A Life, 2nd ed. 1998.
8. ^ Russell, Bertrand (1959), Wisdom of the West, p. 276.
9. ^ a b c Anellis, Irving H. (1995), "Peirce Rustled, Russell Pierced: How Charles Peirce and Bertrand Russell Viewed Each Other's Work in Logic, and an Assessment of Russell's Accuracy and Role in the Historiography of Logic", Modern Logic, 5, 270–328. Arisbe Eprint.
10. ^ Popper, Karl (1972), Objective Knowledge: An Evolutionary Approach, p. 212.
11. ^ Centro de Estudos Peirceanos (CeneP) (M. Lúcia Santaella-Braga, Pontificia Universidade Católica de São Paulo (PUC-SP), Brazil)
12. ^ Represented on the Internet by Commens: Virtual Centre for Peirce Studies at the University of Helsinki
13. ^
• International Research Group on Abductive Inference at the Johann Wolfgang Goethe-Universität Frankfurt am Main (Uwe Wirth, Alexander Roesler; Frankfurt, Germany).
• Theological Research Group in C.S. Peirce's Philosophy (Hermann Deuser, Justus-Liebig-Universität Geissen; Wilfred Haerle, Philipps-Universität Marburg, Germany).
• Research Group on Semiotic Epistemology and Mathematics Education, Institut für Didaktik der Mathematik (Michael Hoffman, Michael Otte, Universität Bielefeld, Germany).
14. ^ Institut de Recherche en Sémiotique, Communication et Éducation (L 'I.R.S.C.E)(Gérard Deledalle, Joëlle Réthoré, Université de Perpignan, France, 1974-2003)
15. ^ Grupo de Estudios Peirceanos GEP (Jaime Nubiola, University of Navarra, Spain)
16. ^ Centro Studi Peirce, Università degli Studi di Milano, Italy. Founded 1998 by Carlo Sini and Rossella Fabbrichesi.
17. ^ Burch, Robert (2001), "Charles Sanders Peirce" in the Stanford Encyclopedia of Philosophy. Revised, Summer 2006.
18. ^ Robin, Richard S. (1967) Annotated Catalogue of the Papers of Charles S. Peirce. Amherst MA: University of Massachusetts Press. PEP Eprint.
19. ^ "The manuscript material now (1997) comes to more than a hundred thousand pages. These contain many pages of no philosophical interest, but the number of pages on philosophy certainly number much more than half of that. Also, a significant but unknown number of manuscripts have been lost." — Joseph Ransdell, 1997, "Some Leading Ideas of Peirce's Semiotic", end note 2, 1997 light revision of 1977 version in Semiotica 19, 1977, pp. 157-178.
20. ^ Houser, Nathan, "The Fortunes and Misfortunes of the Peirce Papers", presented to the Fourth Congress of the International Association for Semiotic Studies, Perpignan, France, 1989. Published in Signs of Humanity, v. 3., Berlin: Mouton de Gruyter, 1992, pp. 1259-1268. Eprint
21. ^ Auspitz, Josiah Lee (1994), "The Wasp Leaves the Bottle: Charles Sanders Peirce", The American Scholar, v.63, n. 4, autumn, 602-618. Arisbe Eprint.
22. ^ a b See the 1978 review by Arthur Burks.
23. ^ "A Boolean Algebra with One Constant", 1880 MS, CP 4.12-20.
24. ^ Peirce, C. S. (1881), "On the Logic of Number", American Journal of Mathematics v. 4, pp. 85-95. Reprinted (CP 3.252-88), (W 4:299-309). See See Shields, Paul (1997), "Peirce’s Axiomatization of Arithmetic", in Houser et al., eds., Studies in the Logic of Charles S. Peirce.
25. ^ Peirce, C.S. (1898), "The Logic of Mathematics in Relation to Education" in Educational Review v. 15, pp. 209-16, Internet Archive Eprint. Reprinted CP 3.553-62. See also his "The Simplest Mathematics" (1902 MS), CP 4.227–323.
26. ^ Lewis, Clarence Irving (1918), A Survey of Symbolic Logic, se ch. 1, § 7 "Peirce", pp. 79-106, see p. 79 via Internet Archive. Note that Lewis's bibliography lists works by Frege, tagged with asterisks as important.
27. ^ a b c Putnam, Hilary (1982), "Peirce the Logician", Historia Mathematica 9, 290–301. Reprinted, pp. 252–60 in Hilary Putnam, Realism with a Human Face, Harvard University Press, Cambridge, MA, 1990. Excerpt with article's last five pages: Eprint.
28. ^ Peirce, C.S. (1885), "On the Algebra of Logic: A Contribution to the Philosophy of Notation", American Journal of Mathematics 7, two parts, first part published 1885, pp. 180–202 (see Houser in linked paragraph in "Introduction" in W 4). Presented, National Academy of Sciences, Newport, RI, 14–17 Oct 1884 (see EP 1, Headnote 16). 1885 is the year usually given for this work. Reprinted (CP 3.359–403), (W 5:162–90), (EP 1:225–8, in part).
29. ^ Letter, Peirce to A. Marquand, W 5:421–4
30. ^ van Heijenoort, Jean (1967), "Logic as Language and Logic as Calculus," Synthese 17: 324–30.
31. ^ Brunning, Jacqueline and Forster, Paul (1997), The Rule of Reason: The Philosophy of C. S. Peirce, U of Toronto Press.
32. ^ Brady, Geraldine (2000), From Peirce to Skolem: A Neglected Chapter in the History of Logic, North-Holland/Elsevier Science BV, Amsterdam, Netherlands.
33. ^ Houser, Nathan, Roberts, Don D., and Van Evra, James (eds., 1997), Studies in the Logic of Charles Sanders Peirce, Indiana University Press, Bloomington, IN.
34. ^ Misak, Cheryl J. (ed., 2004), The Cambridge Companion to Peirce, Cambridge University Press, Cambridge, UK
35. ^ Peirce, C.S., "Analysis of the Methods of Mathematical Demonstration", Memoir 4, Draft C, Manuscript L75.90-102, see 99-100, Eprint and scroll down.
36. ^ See "Peirce's Clarifications on Continuity" by Jérôme Havenel, Transactions Winter 2008 pp. 68-133. From p. 119: "It is on May 26, 1908, that Peirce finally gave up his idea that in every continuum there is room for whatever collection of any multitude. From now on, there are different kinds of continua, which have different properties."
37. ^ Peirce condemned the use of "certain likelihoods" even more strongly than he criticized Bayesian methods. Indeed Peirce used Bayesian inference in criticizing parapsychology.
38. ^ See quotes under "Philosophy" at CDPT, such as EP 2:372-3, CP 1.183-186, and CP 1.239-241.
39. ^ "Minute Logic", CP 2.87, c.1902 and A Letter to Lady Welby, CP 8.329, 1904. See relevant quotes under "Categories, Cenopythagorean Categories" at CDPT.
40. ^ The ground blackness is the pure abstraction of the quality black which in turn amounts to which embodies blackness (in which phrase the quality is formulated as reference to the ground). The point is not merely noun (the ground) versus adjective (the quality), but whether we are considering the black(ness) as abstracted away from application to an object, or instead as so applied (for instance to a stove). Yet note that Peirce's distinction here is not that between a property-general and a property-individual (a trope). See "On a New List of Categories" (1867), in the section appearing in CP 1.551. Regarding the ground, cf. the Scholastic conception of a relation's foundation, Google limited preview Deely 1982, p. 61
41. ^ A quale in this sense is a such, just as a quality is a suchness. Cf. under "Use of Letters" in §3 of Peirce's "Description of a Notation for the Logic of Relatives", Memoirs of the American Academy, v. 9, pp. 317-78 (1870), separately reprinted (1870), from which see p. 6 via Google books, also reprinted in CP 3.63:

Now logical terms are of three grand classes. The first embraces those whose logical form involves only the conception of quality, and which therefore represent a thing simply as “a —.” These discriminate objects in the most rudimentary way, which does not involve any consciousness of discrimination. They regard an object as it is in itself as such (quale); for example, as horse, tree, or man. These are absolute terms. (Peirce, 1870. But also see "Quale-Consciousness", 1898, in CP 6.222-37.)

42. ^ See "Charles S. Peirce on Esthetics and Ethics: A Bibliography" by Kelly A. Parker, of the Department of Philosophy, Grand Valley State University, Allendale, Michigan, USA in 1999. Eprint PDF (145 KiB)
43. ^ a b Peirce (1899), "F.R.L." [First Rule of Logic], CP 1.135-140, Eprint
44. ^ a b Peirce, C.S., 1882, "Introductory Lecture on the Study of Logic" delivered September 1882, Johns Hopkins University Circulars, v. 2, n. 19, pp. 11-12, November 1892, Google Books Eprint. Reprinted (EP 1:214-214; W 4:378-382; CP 7.59-76).
45. ^ "The Doctrine of Chances", Popular Science Monthly, v. 12, pp. 604-615, 1878 (CP 2.645-68, W 3:276-90, EP 1:142-54).

"...death makes the number of our risks, the number of our inferences, finite, and so makes their mean result uncertain. The very idea of probability and of reasoning rests on the assumption that this number is indefinitely great. .... ...logicality inexorably requires that our interests shall not be limited. .... Logic is rooted in the social principle."

46. ^ Peirce, C. S. (1902), "MS L75: Logic, Regarded As Semeiotic (The Carnegie application of 1902): Version 1: An Integrated Reconstruction", Joseph Ransdell, ed., Arisbe Eprint.
47. ^ Peirce, C.S., CP 5.448 footnote, from "The Basis of Pragmaticism" in 1906.
48. ^ a b "To say, therefore, that thought cannot happen in an instant, but requires a time, is but another way of saying that every thought must be interpreted in another, or that all thought is in signs." Peirce, 1868, "Questions Concerning Certain Faculties Claimed for Man", Journal of Speculative Philosophy v. 2 (1868), pp. 103-114. Reprinted (CP 5.213-63, the quote is from para. 253). Arisbe Eprint.
49. ^ See Classification of the sciences (Peirce).
50. ^ For a fuller discussion by Peirce of fallibilism and its powerful ramifications, see "Fallibilism, Continuity, and Evolution", 1897, CP 1.141-75 (Eprint), which the Collected Papers’s editors placed directly after "F.R.L." (1899, CP 1.135-40).
51. ^ Peirce (1902), The Carnegie Institute Application, Memoir 10, MS L75.361-2, Arisbe Eprint.
52. ^ a b Peirce, C.S. (1868), "Some Consequences of Four Incapacities", Journal of Speculative Philosophy v. 2, n. 3, pp. 140–157. Reprinted CP 5.264–317, W 2:211–42 EP 1:28–55. Arisbe Eprint.
53. ^ Peirce, C. S. (1905), "What Pragmatism Is", The Monist, v. XV, n. 2, pp. 161-81. Reprinted CP 5.411-37. Arisbe Eprint
54. ^ Regarding the evolution of the word "semiotic" and its spellings, see Semeiotic#Literature.
55. ^ Peirce 1907, CP 5.484. Reprinted (EP 2:411 in "Pragmatism," 398-433).
56. ^ Peirce, C. S. (1867), "Upon Logical Comprehension and Extension" (CP 2.391-426), (W 2:70-86, PEP Eprint).
57. ^ Peirce, C.S and Ladd-Franklin, Christine, "Signification (and Application, in logic)", Dictionary of Philosophy and Psychology v. 2, p. 528. Reprinted CP 2.431-4.
58. ^ a b See Peirce, C. S. (1868), "What Is Meant By 'Determined'", Journal of Speculative Philosophy v. 2, n. 3, pp. 190-191. Reprinted (CP 6.625-630), (W 2:155-157, PEP Eprint)."
59. ^ Peirce, C.S., "A Letter to Lady Welby" (1908), Semiotic and Significs, pp. 80-81:

I define a Sign as anything which is so determined by something else, called its Object, and so determines an effect upon a person, which effect I call its Interpretant, that the latter is thereby mediately determined by the former. My insertion of "upon a person" is a sop to Cerberus, because I despair of making my own broader conception understood.

60. ^ a b See "76 definitions of the sign by C.S.Peirce", collected by Professor Robert Marty (University of Perpignan, France).
61. ^ "Representamen" (properly with the "a" long and stressed: pronounced /rɛprəzɛnˈteɪmən/) is Peirce's adopted (not coined) technical term for the sign as covered in his theory. Peirce used the technical term in case a divergence should come to light between his theoretical version and the popular senses of the word "sign". He eventually stopped using "representamen". See EP 2:272-3 and Semiotic and Significs p. 193, quotes in "Representamen" at CDPT.
62. ^ Peirce (1909), A Letter to William James, EP 2:498, viewable under "Dynamical Object" at CDPT.
63. ^ Peirce (1909), A Letter to William James, EP 2:492, see under "Object" at CDPT.
64. ^ See pp. 404-9 in "Pragmatism" in EP 2. Ten quotes on collateral observation from Peirce provided by Joseph Ransdell can be viewed here at peirce-l's Lyris archive. Note: Ransdell's quotes from CP 8.178-9 are also in EP 2:493-4, which gives their date as 1909; and his quote from CP 8.183 is also in EP 2:495-6, which gives its date as 1909.
65. ^ See the following quotes under "Abduction" at CDPT:
• On correction of "A Theory of Probable Inference", see the quotes from "Minute Logic", CP 2.102, c. 1902, and from the Carnegie Application (L75), 1902, Historical Perspectives on Peirce's Logic of Science v. 2, pp. 1031-1032.
• On new logical form for abduction, see the quote from Harvard Lectures on Pragmatism, 1903, CP 5.188-189.
See also Santaella, Lucia (c. 2004) "The Development of Peirce's Three Types of Reasoning: Abduction, Deduction, and Induction". Eprint.
66. ^ "Deduction proves that something must be; Induction shows that something actually is operative; Abduction merely suggests that something may be." "Lectures on Pragmatism", 1903, CP 5.171.
67. ^ a b See Pragmaticism#pragfootnote for discussion and references.
68. ^ James, William (1910) Pragmatism: A New Name for Some Old Ways of Thinking.
69. ^ a b "That the rule of induction will hold good in the long run may be deduced from the principle that reality is only the object of the final opinion to which sufficient investigation would lead", in Peirce, C. S. (1878 April), "The Probability of Induction", p. 718 (Internet Archive Eprint) in Popular Science Monthly, v. 12, pp. 705-18. Reprinted (Chance, Love, and Logic, pp. 82-105), (CP 2.669-93), (Philosophical Writings of Peirce, pp. 174-89), (W 3:290-305), (EP 1:155-69).
70. ^ Peirce (1902), CP 5.13 note 1
71. ^ See CP 1.34 Eprint (in "The Spirit of Scholasticism"), where Peirce attributes the success of modern science not so much to a novel interest in verification as to the improvement of verification.
72. ^ See Joseph Ransdell's comments and his tabular list of titles of Peirce's proposed list of memoirs in 1902 for his Carnegie application, Eprint
73. ^ "Philosophy and the Conduct of Life", 1898, Lecture 1 of the Cambridge (MA) Conferences Lectures, published CP 1.616-48 in part and in Reasoning and the Logic of Things, Ketner (ed., intro.) and Putnam (intro., comm.), 105-22, reprinted in EP 2:27-41.
74. ^ Peirce, C. S. (1903), "Pragmatism -- The Logic of Abduction", CP 5.195-205, especially para. 196. Eprint.
75. ^ a b c Peirce, C. S. (1908), "A Neglected Argument for the Reality of God", published in part, Hibbert Journal v. 7, 90-112, Hibbert Journal version, also at Internet Archive Eprint. Reprinted with one or another unpublished part in CP 6.452-485, Selected Writings pp. 358-379, EP 2:434-450, Peirce on Signs pp. 260-278. Eprint.
76. ^ Peirce (c. 1906), "PAP (Prolegomena for an Apology to Pragmatism)" (MS 293), NEM 4:319-320, see first quote under "Abduction" at CDPT.
77. ^ See MS L75.329-330, from Draft D of Memoir 27 of Peirce's application to the Carnegie Institution:

Consequently, to discover is simply to expedite an event that would occur sooner or later, if we had not troubled ourselves to make the discovery. Consequently, the art of discovery is purely a question of economics. The economics of research is, so far as logic is concerned, the leading doctrine with reference to the art of discovery. Consequently, the conduct of abduction, which is chiefly a question of heuretic and is the first question of heuretic, is to be governed by economical considerations.

78. ^ In addition to Peirce's "Neglected Argument" cited above, see Nubiola, Jaime (2004) "Il Lume Naturale: Abduction and God", Semiotiche I/2, 91-102. Eprint.
79. ^ Peirce, C. S. (1868), "Nominalism versus Realism", Journal of Speculative Philosophy v. 2, n. 1, pp. 57-61. Reprinted (CP 6.619-624), (W 2:144-153, PEP Eprint).
80. ^ On Peirce's moderate, then strong modal realism, see:
• Peirce, C. S. (1897), "The Logic of Relatives", The Monist, v. VII, n. 2 pp. 161-217, The Open Court Publishing Co., Chicago, IL, January 1897. Reprinted (CP 3.456-552). See especially p. 206 (CP 3.527) Google Books Eprint.
• Peirce, C. S. (1905), "Issues of Pragmaticism", The Monist, v. XV, n. 4, pp. 481–499, The Open Court Publishing Co., Chicago, IL, October 1905. Reprinted (CP 5.438-463), (SW 203-226). See especially pp. 495–6 (CP 5.453–7) Google Books Eprint.
• Peirce, C. S. (c. 1905), Letter to Signor Calderoni, CP 8.205–213, especially 208.
• Lane, Robert (2007), "Peirce's Modal Shift: From Set Theory to Pragmaticism", Journal of the History of Philosophy, v. 45, n. 4, Oct.
81. ^ Peirce in his 1906 "Answers to Questions concerning my Belief in God", CP 6.495, Eprint, reprinted in part as "The Concept of God" in Philosophical Writings of Peirce, J. Buchler, ed., 1940, pp. 375-378:

I will also take the liberty of substituting "reality" for "existence." This is perhaps overscrupulosity; but I myself always use exist in its strict philosophical sense of "react with the other like things in the environment." Of course, in that sense, it would be fetichism to say that God "exists." The word "reality," on the contrary, is used in ordinary parlance in its correct philosophical sense. [....] I define the real as that which holds its characters on such a tenure that it makes not the slightest difference what any man or men may have thought them to be, or ever will have thought them to be, here using thought to include, imagining, opining, and willing (as long as forcible means are not used); but the real thing's characters will remain absolutely untouched"

82. ^ Peirce, "The Architecture of Theories", The Monist 1 (1891), pp. 161–176, see p. 170, via the Internet Archive). Reprinted (CP 6.7–34) and (EP 1:285-297, see p. 293).
83. ^ See "tychism", "tychasm", "tychasticism", and the rest, at CDPT.
84. ^ Peirce, "Evolutionary Love", The Monist, v. 3, pp. 176-200 (1893). Reprinted CP 6.278-317, EP 1:352-72. Arisbe Eprint
85. ^ See p. 115 in Reasoning and the Logic of Things, Ketner, ed., 1992, from Peirce's 1898 lectures.
86. ^ Peirce (1903), CP 1.182 Eprint and Peirce (1906) 'The Basis of Pragmaticism', EP 2:372-3, see "Philosophy" at CDPT.

 Arisbe: The Peirce Gateway, Joseph Ransdell, ed. 95 online works by Peirce as of 2/17/09, with annotations. 100s of online papers on Peirce. The peirce-l e-forum. Much else. Centro de Estudos Peirceanos (CeneP) and Centro Internacional de Estudos Peirceanos (CIEP), Lucia Santaella et al., Pontifical Catholic U. of São Paulo (PUC-SP), Brazil. In Portuguese, some English. Centro Studi Peirce, Carlo Sini, Rossella Fabbrichesi, et al., U. of Milan, Italy. In Italian and English. Part of Pragma with European Journal of Pragmatism and American Philosophy. Charles S. Peirce Society Transactions of the Charles S. Peirce Society. Quarterly journal of Peirce studies since spring 1965. Table of Contents of all issues. Charles S. Peirce Studies, Brian Kariger, ed. Commens: Virtual Centre for Peirce Studies, U. of Helsinki, Mats Bergman & Sami Paavola, eds. 24 papers by ten authors as of 1/31/09. Plus the Commens Dictionary of Peirce's Terms (CDPT) with Peirce's own definitions, often many per term across the decades. Conceptual graphs, knowledge representation. John F. Sowa, ed. Related: Conceptual Graphs. Conceptual Structures, holding yearly international conferences. Digital Encyclopedia of Charles S. Peirce. João Queiroz & Ricardo Gudwin, eds., Brazil, in English. 84 authors listed, 51 papers online, more papers listed, as of 1/31/09. Existential Graphs, Jay Zeman, ed., U. of Florida. With 4 works by Peirce. Grupo de Estudios Peirceanos, Jaime Nubiola, ed., U. of Navarra, Spain. Big study site, in Spanish and English, many papers, bibliography, more. His Glassy Essence. Autobiographical Peirce. Kenneth Laine Ketner. Institute for Studies in Pragmaticism, Kenneth Laine Ketner, Clyde Hendrick, et al., Texas Tech U. International Association for Semiotic Studies, its journal: Semiotica. International Pragmatism Society, its journal: Contemporary Pragmatism. International Research Group on Abductive Inference, Uwe Wirth and Alexander Roesler, eds. Uses frames. Click on link at bottom of its home page for English. Laboratory for Artificial Intelligence Research: Abductive Inference in Reasoning and Perception, John R. Josephson, Ohio State U. Nordic Pragmatism Network, Henrik Rydenfelt (U. of Helsinki), coordinator. Open Semiotics Resource Center. Free online journals, lecture courses, and more. Peirce at Signo: Theoretical Semiotics on the Web, Louis Hébert, director, supported by U of Québec. Theory, application, exercises of Peirce's Semiotics and Esthetics. English, French. Peirce Edition Project (PEP), Indiana U.-Purdue U. Indianapolis (IUPUI). Editors of the Writings of Charles S. Peirce (W) and The Essential Peirce v. 2. Many study aids such as introductions to EP 1–2 and W 1–6, and the Robin Catalog of Peirce's manuscripts and letters. Most of W 2 readable online. PEP’s branch at Université du Québec à Montréal (UQÀM). Working on W 7: Peirce's work on the Century Dictionary. Definition of the week. Peirce's Existential Graphs, Frithjof Dau, Germany Peirce's Theory of Semiosis, Joseph Esposito. Free online course. Pragmatism Cybrary, John R. Shook, ed. Semiotic Society of America, its journal: American Journal of Semiotics. Semiotics according to Robert Marty, with 76 definitions of the sign by Peirce. Sign Systems Studies, Peeter Torop, Mihhail Lotman, Kalevi Kull, eds., U. of Tartu, Estonia. Signs - International Journal of Semiotics. Martin Thellefsen & Torkild Thellefsen, chief editors. In the Net of Abductions (On Juliette Peirce's Identity), Vitaly Kiryushchenko, Russia. Also see Juliette Peirce#Literature. Discovering the American Aristotle, Eward T. Oakes

Charles Sanders Peirce bibliography has numerous external links throughout to Peirce materials readable online, including:

An earlier version of this article, by Jaime Nubiola, was posted at Nupedia.

 Logic Statistics Philosophy of science Metaphysics

# Quotes

Up to date as of January 14, 2010

### From Wikiquote

It is the man of science, eager to have his every opinion regenerated, his every idea rationalized, by drinking at the fountain of fact, and devoting all the energies of his life to the cult of truth, not as he understands it, but as he does not yet understand it, that ought properly to be called a philosopher.
It is important to understand what I mean by semiosis.

Charles Sanders Peirce [pronounced like purse] () was an American philosopher, chemist and polymath, who is now remembered as a pioneer of the field of semiotics and, with the formulation of the pragmatic maxim, the founder of the philosophies of Pragmatism and Pragmaticism. He was the son of the mathematician Benjamin Peirce.

## Sourced

By an object, I mean anything that we can think, i.e. anything we can talk about.
The entire universe is perfused with signs, if it is not composed exclusively of signs.
• The consciousness of a general idea has a certain "unity of the ego" in it, which is identical when it passes from one mind to another. It is, therefore, quite analogous to a person, and indeed, a person is only a particular kind of general idea.
• "Man's Glassy Essence" in The Monist, Vol. III, No. 1 (October 1892)
• It is the man of science, eager to have his every opinion regenerated, his every idea rationalized, by drinking at the fountain of fact, and devoting all the energies of his life to the cult of truth, not as he understands it, but as he does not yet understand it, that ought properly to be called a philosopher. To an earlier age knowledge was power — merely that and nothing more; to us it is life and the summum bonum. Emancipation from the bonds of self, of one's own prepossessions, importunately sought at the hands of that rational power before which all must ultimately bow, — this is the characteristic that distinguishes all the great figures of nineteenth-century science from those of former periods.
• "The Century's Great Men in Science" in The 19th Century : A Review of Progress During the Past One Hundred Years in the Chief Departments of Human Activity (1901), published by G. P. Putnam's Sons.
• You are of all my friends the one who illustrates pragmatism in its most needful forms. You are a jewel of pragmatism.
• Letter to William James (16 March 1903), published in The thought and character of William James, as revealed in unpublished correspondence and notes (1935) by Ralph Barton Perry, Vol. 2, p. 427
• It is important to understand what I mean by semiosis. All dynamic action, or action of brute force, physical or psychical, either takes place between two subjects, — whether they react equally upon each other, or one is agent and the other patient, entirely or partially, — or at any rate is a resultant of such actions between pairs. But by "semiosis" I mean, on the contrary, an action, or influence, which is, or involves, a cooperation of three subjects, such as a sign, its object, and its interpretant, this tri-relative influence not being in any way resolvable into actions between pairs.
• "Pragmatism" (1907) in The Essential Peirce : Selected Philosophical Writings (1998) edited by the Peirce Edition Project, Vol. 2, p. 411, Indiana University Press.
• I define a Sign as anything which is so determined by something else, called its Object, and so determines an effect upon a person, which effect I call its Interpretant, that the latter is thereby mediately determined by the former.
• It has never been in my power to study anything, — mathematics, ethics, metaphysics, gravitation, thermodynamics, optics, chemistry, comparative anatomy, astronomy, psychology, phonetics, economics, the history of science, whist, men and women, wine, metrology, except as a study of semeiotic.
• The definition of definition is at bottom just what the maxim of pragmatism expresses.
• By an object, I mean anything that we can think, i.e. anything we can talk about.
• "Reflections on Real and Unreal Objects", Undated, MS 966
• The entire universe is perfused with signs, if it is not composed exclusively of signs.
• Quoted in Essays in Zoosemiotics (1990) by Thomas A. Sebeok

### On The Algebra of Logic (1885)

"On The Algebra of Logic : A Contribution to the Philosophy of Notation" in The American Journal of Mathematics 7 (1885), p. 180 - 202
A sign is in a conjoint relation to the thing denoted and to the mind.
The index asserts nothing; it only says "There!" It takes hold of our eyes, as it were, and forcibly directs them to a particular object, and there it stops.
The actual world cannot be distinguished from a world of imagination by any description. Hence the need of pronoun and indices, and the more complicated the subject the greater the need of them.
• Any character or proposition either concerns one subject, two subjects, or a plurality of subjects. For example, one particle has mass, two particles attract one another, a particle revolves about the line joining two others. A fact concerning two subjects is a dual character or relation; but a relation which is a mere combination of two independent facts concerning the two subjects may be called degenerate, just as two lines are called a degenerate conic. In like manner a plural character or conjoint relation is to be called degenerate if it is a mere compound of dual characters.
A sign is in a conjoint relation to the thing denoted and to the mind. If this triple relation is not of a degenerate species, the sign is related to its object only in consequence of a mental association, and depends upon a habit. Such signs are always abstract and general, because habits are general rules to which the organism has become subjected. They are, for the most part, conventional or arbitrary. They include all general words, the main body of speech, and any mode of conveying a judgment. For the sake of brevity I will call them tokens.
• If the sign were not related to its object except by the mind thinking of them separately, it would not fulfil the function of a sign at all. Supposing, then, the relation of the sign to its object does not lie in a mental association, there must be a direct dual relation of the sign to its object independent of the mind using the sign. In the second of the three cases just spoken of, this dual relation is not degenerate, and the sign signifies its object solely by virtue of being really connected with it. Of this nature are all natural signs and physical symptoms. I call such a sign an index, a pointing finger being the type of the class.
The index asserts nothing; it only says "There!" It takes hold of our eyes, as it were, and forcibly directs them to a particular object, and there it stops.
Demonstrative and relative pronouns are nearly pure indices, because they denote things without describing them; so are the letters on a geometrical diagram, and the subscript numbers which in algebra distinguish one value from another without saying what those values are.
• I call a sign which stands for something merely because it resembles it, an icon. Icons are so completely substituted for their objects as hardly to be distinguished from them. Such are the diagrams of geometry. A diagram, indeed, so far as it has a general signification, is not a pure icon; but in the middle part of our reasonings we forget that abstractness in great measure, and the diagram is for us the very thing. So in contemplating a painting, there is a moment when we lose the consciousness that it is not the thing, the distinction of the real and the copy disappears, and it is for the moment a pure dream, — not any particular existence, and yet not general. At that moment we are contemplating an icon.
• I have taken pains to make my distinction of icons, indices, and tokens clear, in order to enunciate this proposition: in a perfect system of logical notation signs of these several kinds must all be employed. Without tokens there would be no generality in the statements, for they are the only general signs; and generality is essential to reasoning. ... But tokens alone do not state what is the subject of discourse ; and this can, in fact, not be described in general terms ; it can only be indicated. The actual world cannot be distinguished from a world of imagination by any description. Hence the need of pronoun and indices, and the more complicated the subject the greater the need of them.
• Now, to say that a lot of objects is finite, is the same as to say that if we pass through the class from one to another we shall necessarily come round to one of those individuals already passed; that is, if every one of the lot is in any one-to-one relation to one of the lot, then to every one of the lot some one is in this same relation.

Mathematical Monads (23 January 1889) published in Writings of Charles S. Peirce: A Chronological Edition (1982) edited by Max Harold Fisch, Vol. 6
"It lightens and it thunders," is conjunctive, "It lightens or it thunders" is disjunctive. Each such individual act of connecting a pair of statements is a new monad for the mathematician.
• As the mathematics are now understood, each branch — or, if you please, each problem, — is but the study of the relations of a collection of connected objects, without parts, without any distinctive characters, except their names or designating letters. These objects are commonly called points; but to remove all notion of space relations, it may be better to name them monads. The relations between these points are mere complications of two different kinds of elementary relations, which may be termed immediate connection and immediate non-connection. All the monads except as serve as intermediaries for the connections have distinctive designations.
• p. 268
• A pair of statements may be taken conjunctively or disjunctively; for example, "It lightens and it thunders," is conjunctive, "It lightens or it thunders" is disjunctive. Each such individual act of connecting a pair of statements is a new monad for the mathematician.
• p. 268

### The Architecture of Theories (1891)

First published in The Monist Vol. I, No. 2 (January 1891), p. 161
I think we may safely say that the studies preliminary to the construction of a great theory should be at least as deliberate and thorough as those that are preliminary to the building of a dwelling-house.
Uniformities are precisely the sort of facts that need to be accounted for.
Feelings, by being excited, become more easily excited, especially in the ways in which they have previously been excited.
May some future student go over this ground again, and have the leisure to give his results to the world.
• Of the fifty or hundred systems of philosophy that have been advanced at different times of the world's history, perhaps the larger number have been, not so much results of historical evolution, as happy thoughts which have accidently occurred to their authors. An idea which has been found interesting and fruitful has been adopted, developed, and forced to yield explanations of all sorts of phenomena. ... The remaining systems of philosophy have been of the nature of reforms, sometimes amounting to radical revolutions, suggested by certain difficulties which have been found to beset systems previouslv in vogue; and such ought certainly to be in large part the motive of any new theory. ... When a man is about to build a house, what a power of thinking he has to do, before he can safely break ground! With what pains he has to excogitate the precise wants that are to be supplied. What a study to ascertain the most available and suitable materials, to determine the mode of construction to which those materials are best adapted, and to answer a hundred such questions! Now without riding the metaphor too far, I think we may safely say that the studies preliminary to the construction of a great theory should be at least as deliberate and thorough as those that are preliminary to the building of a dwelling-house.
• To suppose universal laws of nature capable of being apprehended by the mind and yet having no reason for their special forms, but standing inexplicable and irrational, is hardly a justifiable position. Uniformities are precisely the sort of facts that need to be accounted for. That a pitched coin should sometimes turn up heads and sometimes tails calls for no particular explanation; but if it shows heads every time, we wish to know how this result has been brought about. Law is par excellence the thing that wants a reason.
• The only possible way of accounting for the laws of nature and for uniformity in general is to suppose them results of evolution. This supposes them not to be absolute, not to be obeyed precisely. It makes an element of indeterminacy, spontaneity, or absolute chance in nature. Just as, when we attempt to verify any physical law, we find our observations cannot be precisely satisfied by it, and rightly attribute the discrepancy to errors of observation, so we must suppose far more minute discrepancies to exist owing to the imperfect cogency of the law itself, to a certain swerving of the facts from any definite formula.
• The one primary and fundamental law of mental action consists in a tendency to generalisation. Feeling tends to spread ; connections between feelings awaken feelings; neighboring feelings become assimilated; ideas are apt to reproduce themselves. These are so many formulations of the one law of the growth of mind. When a disturbance of feeling takes place, we have a consciousness of gain, the gain of experience; and a new disturbance will be apt to assimilate itself to the one that preceded it. Feelings, by being excited, become more easily excited, especially in the ways in which they have previously been excited. The consciousness of such a habit constitutes a general conception.
The cloudiness of psychological notions may be corrected by connecting them with physiological conceptions. Feeling may be supposed to exist, wherever a nerve-cell is in an excited condition. The disturbance of feeling, or sense of reaction, accompanies the transmission of disturbance between nerve-cells or from a nerve-cell to a muscle-cell or the external stimulation of a nerve-cell. General conceptions arise upon the formation of habits in the nerve-matter, which are molecular changes consequent upon its activity and probably connected with its nutrition.
• The law of habit exhibits a striking contrast to all physical laws in the character of its commands. A physical law is absolute. What it requires is an exact relation. Thus, a physical force introduces into a motion a component motion to be combined with the rest by the parallelogram of forces; but the component motion must actually take place exactly as required by the law of force. On the other hand, no exact conformity is required by the mental law. Nay, exact conformity would be in downright conflict with the law ; since it would instantly crystallise thought and prevent all further formation of habit. The law of mind only makes a given feeling more likely to arise. It thus resembles the "non-conservative" forces of physics, such as viscosity and the like, which are due to statistical uniformities in the chance encounters of trillions of molecules.
• The old dualistic notion of mind and matter, so prominent in Cartesianism, as two radically different kinds of substance, will hardly find defenders to-day. Rejecting this, we are driven to some form of hylopathy, otherwise called monism.
• The one intelligible theory of the universe is that of objective idealism, that matter is effete mind, inveterate habits becoming physical laws. But before this can be accepted it must show itself capable of explaining the tridimensionality of space, the laws of motion, and the general characteristics of the universe, with mathematical clearness and precision ; for no less should be demanded of every Philosophy.
• Three conceptions are perpetually turning up at every point in every theory of logic, and in the most rounded systems they occur in connection with one another. They are conceptions so very broad and consequently indefinite that they are hard to seize and may be easily overlooked. I call them the conceptions of First, Second, Third. First is the conception of being or existing independent of anything else. Second is the conception of being relative to, the conception of reaction with, something else. Third is the conception of mediation, wherebv a first and second are brought into relation.
• The origin of things, considered not as leading to anything, but in itself, contains the idea of First, the end of things that of Second, the process mediating between them that of Third. A philosophy which emphasises the idea of the One, is generally a dualistic philosophy in which the conception of Second receives exaggerated attention: for this One (though of course involving the idea of First) is always the other of a manifold which is not one. The idea of the Many, because variety is arbitrariness and arbitrariness is repudiation of any Secondness, has for its principal component the conception of First. In psychology Feeling is First, Sense of reaction Second, General conception Third, or mediation. In biology, the idea of arbitrary sporting is First, heredity is Second, the process whereby the accidental characters become fixed is Third. Chance is First, Law is Second, the tendency to take habits is Third. Mind is First, Matter is Second, Evolution is Third.
• May some future student go over this ground again, and have the leisure to give his results to the world.

### The Doctrine of Necessity Examined (1892)

To "postulate" a proposition is no more than to hope it is true.
First published in The Monist Vol. II, No. 3 (April 1892), p. 321
• When I have asked thinking men what reason they had to believe that every fact in the universe is precisely determined by law, the first answer has usually been that the proposition is a "presupposition " or postulate of scientific reasoning. Well, if that is the best that can be said for it, the belief is doomed. Suppose it be " postulated " : that does not make it true, nor so much as afford the slightest rational motive for yielding it any credence. It is as if a man should come to borrow money, and when asked for his security, should reply he "postulated " the loan. To "postulate" a proposition is no more than to hope it is true. There are, indeed, practical emergencies in which we act upon assumptions of certain propositions as true, because if they are not so, it can make no difference how we act. But all such propositions I take to be hypotheses of individual facts. For it is manifest that no universal principle can in its universality be compromised in a special case or can be requisite for the validity of any ordinary inference.

### The Law of Mind (1892)

First published in The Monist Vol. II, No. 4 (July 1892), p. 533
A serious student of philosophy will be in no haste to accept or reject this doctrine; but he will see in it one of the chief attitudes which speculative thought may take, feeling that it is not for an individual, nor for an age, to pronounce upon a fundamental question of philosophy. That is a task for a whole era to work out.
The tendency to regard continuity, in the sense in which I shall define it, as an idea of prime importance in philosophy conveniently may be be termed synechism.
We are accustomed to speak of ideas as reproduced, as passed from mind to mind, as similar or dissimilar to one another, and, in short, as if they were substantial things; nor can any reasonable objection be raised to such expressions.
Some minds will jump here jump to the conclusion that a past idea cannot in any sense be present. But that is hasty and illogical. How extravagant too, to pronounce our whole knowledge of the past to be mere delusion!
In the case of colors, there is a tridimensional spread of feelings.
The first character of a general idea … is that it is living feeling … in its absence of boundedness a vague possibility of more than is present is directly felt.
The uncertainty of the mental law is no mere defect of it, but is on the contrary of its essence. The truth is, the mind is not subject to "law," in the same rigid sense that matter is.
There always remains a certain amount of arbitrary spontaneity in its action, without which it would be dead.
• In an article published in The Monist for January, 1891, I endeavored to show what ideas ought to form the warp of a system of philosophy, and particularly emphasized that of absolute chance. In the number of April, 1892, I argued further in favor of that way of thinking, which it will be convenient to christen tychism (from τύχη, chance). A serious student of philosophy will be in no haste to accept or reject this doctrine; but he will see in it one of the chief attitudes which speculative thought may take, feeling that it is not for an individual, nor for an age, to pronounce upon a fundamental question of philosophy. That is a task for a whole era to work out. I have begun by showing that tychism must give birth to an evolutionary cosmology, in which all the regularities of nature and of mind are regarded as products of growth, and to a Schelling-fashioned idealism which holds matter to be mere specialized and partially deadened mind.
• The tendency to regard continuity, in the sense in which I shall define it, as an idea of prime importance in philosophy conveniently may be be termed synechism. The present paper is intended chiefly to show what synechism is, and what it leads to.
• Logical analysis applied to mental phenomenon shows that there is but one law of mind, namely that ideas tend to spread continuously and to affect certain others which stand to them in a peculiar relation of affectibility. In this spreading they lose intensity, and especially the power of affecting others, but gain generality and become welded with other ideas.
• We are accustomed to speak of ideas as reproduced, as passed from mind to mind, as similar or dissimilar to one another, and, in short, as if they were substantial things; nor can any reasonable objection be raised to such expressions. But taking the word "idea" in the sense of an event in an individual consciousness, it is clear that an idea once past is gone forever, and any supposed recurrence of it is another idea. These two ideas are not present in the same state of consciousness, and therefore cannot possibly be compared.
• What distinct meaning can attach to saying that an idea in the past in any way affects an idea in the future, from which it is completely detached?
• We have here a question of difficulty, analogous to the question of nominalism and realism.
• Some minds will jump here jump to the conclusion that a past idea cannot in any sense be present. But that is hasty and illogical. How extravagant too, to pronounce our whole knowledge of the past to be mere delusion! Yet it would seem that the past is completely beyond the bounds of possible experience as a Kantian thing-in-itself.
• How can a past idea be present?... it can only be going, infinitesimally past, less past than any assignable past date. We are thus brought to the conclusion that the present is connected to the past by a series of real infinitesimal steps.
• If the sensation that precedes the present by half a second were still immediately before me, then on the same principle, the sensation preceding that would be immediately present, and so on ad infinitum. Now, since there is a time [period], say a year, at the end of which an idea is no longer ipso facto present, it follows that this is true of any finite interval, however short.
• Consciousness must essentially cover an interval of time; for if it did not, we could gain no knowledge of time, and not merely no veracious cognition of it, but no conception whatever. We are therefore, forced to say that we are immediately conscious through an infinitesimal interval of time.
• In fact, this infinitesimally spread-out consciousness is a direct feeling of its contents as spread out. In an infinitesimal interval we directly perceive the temporal sequence of its beginning, middle, and end... Now upon this interval follows another, whose beginning is the middle of the former, and whose middle is the end of the former. Here we have an immediate perception of the temporal sequence of its beginning, middle and end, or say, of the second, third, and fourth instants.
• From these two immediate perceptions, we gain a mediate, or inferential perception of the relation of all four instants. This mediate perception is objectively, or as to the object being represented, spread over the four instants; but subjectively, or as itself the subject of duration, it is completely embraced in the second moment. (The reader will observe that I use the word instant to mean a point in time, and moment to mean an infinitesimal duration.
• Now, let there be an indefinite succession of these inferential acts of comparative perception; and it is plain that the last moment will contain objectively the whole series. Let there be, not merely an indefinite succession, but a continuous flow of inference through a finite time; and the result will be a mediate objective consciousness of the whole time in the last moment. In this last moment, the whole series will be recognized, or known as known before.
• Indeed, even this last moment will be recognized like the rest, at least, be just beginning to be so.
• Suppose a surface to be part red and part blue; so that every point on it is either red or blue, and of course, no part can be both red and blue. What then, is the color of the surface in the immediate neighborhood of the point. ...it follows that the boundary is half red and half blue. In like manner, we find it necessary to hold that consciousness essentially occupies time... Thus, the present is half past and half time to come. ...Take another case: the velocity of a particle at any instant of time is its mean velocity during an infinitesimal instant in which that time is consumed. Just so, my immediate feeling is my feeling through an infinitesimal duration containing the present instant.
• One of the most marked features about the law of mind is that it makes time to have a definite direction of flow from past to future. ...This makes one of the great contrasts between the law of mind and the law of physical force, where there is no more distinction between the two opposite directions in time than between moving northward and moving southward.
• Time with its continuity logically involves some other kind of continuity than its own. Time, as the universal form of change, cannot exist unless there is something to undergo change, and to undergo a change continuous in time, there must be a continuity of changeable qualities.
• The development of the human mind has practically extinguished all feelings, except a few sporadic kinds, [like] sound, colors, smells, warmth, etc., which now appear to be disconnected and separate.
• In the case of colors, there is a tridimensional spread of feelings. Originally all feelings may have been connected in the same way, and the presumption is that the number of dimensions was endless. For development essentially involves a limitation of possibilities. But given a number of dimensions of feeling, all possible varieties are obtainable by varying the intensities of the different elements.
• Accordingly, time logically supposes a continuous range of intensity of feeling. It follows then, from the definition of continuity, that when any particular kind of feeling is present, an infinitesimal continuum of all feelings differing infinitesimally from that, is present.
• Since space is continuous, it follows that there must be an immediate community of feeling between parts of mind infinitesimally close together. Without this, I believe it would have been impossible for any co-ordination to be established in the action of the nerve-matter of one brain.
• A finite interval of time generally contains an innumerable series of feelings; and when these become welded together in association the result is a general idea.
• The first character of a general idea so resulting is that it is living feeling. A continuum of this feeling, infinitesimal in duration, but still embracing innumerable parts, and also, though infinitesimal, entirely unlimited, is immediately present. And in its absence of boundedness a vague possibility of more than is present is directly felt.
• Second, in the presence of this continuity of feeling, nominalistic maxims appear futile. There is no doubt about one idea affecting another, when we can directly perceive the one generally modified and shaping itself into the other. Nor can there any longer be any difficulty about one idea resembling another, when we can pass along the continuous field of quality from one to the other and back again to the point which we had marked.
• Third, consider the insistency of an idea. The insistency of a past idea with reference to the present is a quantity which is less, the further back that past idea is, and rises to infinity as the past idea is brought up into coincidence with the present.
• Here we must make one of those inductive applications of the law of continuity which have produced such great results in all of the positive sciences. We must extend the law of insistency into the future. Plainly, the insistency of a future idea with reference to the present is a quantity affected by the minus sign; for it is the present that affects the future, if there be any effect, not the future that affects the present.
• Feeling which has not yet emerged into immediate consciousness is already affectible and already affected. In fact, this is habit, by virtue of which an idea is brought up into the present consciousness by a bond that has already been established between it and another idea while it was still in futuro.
• Wherever ideas come together they tend to weld into general ideas; and whenever they are generally connected, general ideas govern the connection; and these general ideas are living feelings spread out.
• In deduction the mind is under the dominion of a habit or association by virtue of which a general idea suggests in each case a corresponding reaction. This is the way the hind legs of a frog separated from the rest of the body, reason, when you pinch them. It is the lowest form of psychical manifestation.
• But no mental action seems necessary or invariable in its character. In whatever manner the mind has reacted under a given sensation, in that manner it is the more likely to react again; were this, however, an absolute necessity, habits would become wooden and ineradicable, and no room being left for the formulation of new habits, intellectual life would come to a speedy close. Thus, the uncertainty of the mental law is no mere defect of it, but is on the contrary of its essence. The truth is, the mind is not subject to "law," in the same rigid sense that matter is. It only experiences gentle forces which merely render it more likely to act a given way than it otherwise would be. There always remains a certain amount of arbitrary spontaneity in its action, without which it would be dead.
• Let me now try to gather up all these odds and ends of commentary and restate the law of mind, in a unitary way.
• First then, we find that when we regard ideas from a nominalistic, individualistic, sensualistic way, the simplest facts of mind become utterly meaningless. That one idea should resemble another or influence another, or that one state of mind should so much as be thought of in another is, from that standpoint, sheer nonsense.
• Second, by this and other means we are driven to perceive, what is quite evident in itself, that instantaneous feelings flow together in a continuum of feeling, which has in a modified degree the peculiar vivacity of feeling and has gained generality. And in reference to such general ideas, or continua of feeling, the difficulties about resemblance and suggestion and reference to the external, cease to have any force.
• Third, these general ideas are not mere words, nor do they consist in this, that certain concrete facts will every time happen under certain descriptions of conditions; but they are just as much, or rather far more, living realities than the feelings themselves out of which they are concreted. And to say that mental phenomenon are governed by law does not mean merely that they are describable by a general formula; but that there is a living idea, a conscious continuum of feeling which pervades them, and to which they are docile.
• Fourth, this supreme law, which is celestial and living harmony, does not so much as demand that the special ideas shall surrender their peculiar arbitrariness and caprice entirely; for that would be self-destructive. It only requires that they influence and be influenced by one another.
• Fifth, in what measure this unification acts, seems to be regulated only by special rules; or, at least, we cannot in our present knowledge say how far it goes. But it may be said that, judging by appearances, the amount of arbitrariness in the phenomenon of human minds is neither altogether trifling nor very prominent.
• Were the ends of a person already explicit, there would be no room for development, for growth, for life; and consequently there would be no personality. The mere carrying out of predetermined purposes is mechanical. This remark has an application to the philosophy of religion. It is that genuine evolutionary philosophy, that is, one that makes the principle of growth a primordial element of the universe, is so far from being antagonistic to the idea of a personal creator, that it is really inseparable from that idea; while a necessitarian religion is in an altogether false position and is destined to become disintegrated. But a pseudo-evolutionism which enthrones mechanical law above the principle of growth is at once scientifically unsatisfactory, as giving no possible hint of how the universe has come about, and hostile to all hopes of personal relations to God.
• The recognition by one person of another's personality takes place by means to some extent identical to the means by which he is conscious of his own personality. The idea of the second personality, which is as much as to say that second personality itself, enters within the direct consciousness of the first person, and is immediately perceived as his ego, though less strongly. At the same time, the opposition between the two persons is perceived, so that the externality of the second is perceived.
• But the extraordinary insight which some persons are able to gain of others from indications so slight that it is difficult to ascertain what they are, is certainly rendered more comprehensible by the view here taken.
• A difficulty which confronts the synechistic philosophy is this. In considering personality, that philosophy is forced to accept the doctrine of a personal God; but in considering communication, it cannot but admit that if there is a personal God, we must have a direct perception of that person and indeed be in personal communication with him. Now, if that be the case, the question arises how it is possible that the existence of this being should ever have been doubted by anybody. The only answer that I can at present make is that facts stand before our face and eves and stare us in the face are far from being, in all cases, the ones most easily discerned. That has been remarked since time immemorial.
• I think that I have succeeded in making it clear that this doctrine gives room for explanations of many facts which without it are absolutely and hopelessly inexplicable; and further that it carries along with it the following doctrines: first, a logical realism of the most pronounced type; second, objective idealism; third, tychism, with its consequent thoroughgoing evolutionism. We also notice that the doctrine presents no hindrences to spiritual influences, such as some philosophies are felt to do.

### Pragmatism and Pragmaticism (1903)

Lectures on Pragmatism delivered in Cambridge, Massachusetts (26 March - 17 May 1903)
A certain maxim of Logic which I have called Pragmatism has recommended itself to me for diverse reasons and on sundry considerations. Having taken it as my guide for most of my thought, I find that as the years of my knowledge of it lengthen, my sense of the importance of it presses upon me more and more.
In all the works on pedagogy that ever I read — and they have been many, big, and heavy — I don't remember that any one has advocated a system of teaching by practical jokes, mostly cruel. That, however, describes the method of our great teacher, Experience.
Understand me well. My appeal is to observation — observation that each of you must make for himself.
You will mark the limitation of my approval of Ockham's razor. It is a sound maxim of scientific procedure. If the question be what one ought to believe, the logic of the situation must take other factors into account.
Ockham's razor is not worth the stout belief of any common seaman. For stout belief may happen to save the ship, while Entia non sunt multiplicanda praeter necessitatem would be only a stupid way of spelling Shipwreck.
• A certain maxim of Logic which I have called Pragmatism has recommended itself to me for diverse reasons and on sundry considerations. Having taken it as my guide for most of my thought, I find that as the years of my knowledge of it lengthen, my sense of the importance of it presses upon me more and more. If it is only true, it is certainly a wonderfully efficient instrument. It is not to philosophy only that it is applicable. I have found it of signal service in every branch of science that I have studied. My want of skill in practical affairs does not prevent me from perceiving the advantage of being well imbued with pragmatism in the conduct of life.
• Lecture I : Pragmatism : The Normative Sciences, CP 5.14
• Be it understood, then, that what we have to do, as students of phenomenology, is simply to open our mental eyes and look well at the phenomenon and say what are the characteristics that are never wanting in it, whether that phenomenon be something that outward experience forces upon our attention, or whether it be the wildest of dreams, or whether it be the most abstract and general of the conclusions of science.
The faculties which we must endeavor to gather for this work are three. The first and foremost is that rare faculty, the faculty of seeing what stares one in the face, just as it presents itself, unreplaced by any interpretation, unsophisticated by any allowance for this or for that supposed modifying circumstance. This is the faculty of the artist who sees for example the apparent colors of nature as they appear. When the ground is covered by snow on which the sun shines brightly except where shadows fall, if you ask any ordinary man what its color appears to be, he will tell you white, pure white, whiter in the sunlight, a little greyish in the shadow. But that is not what is before his eyes that he is describing; it is his theory of what ought to be seen. The artist will tell him that the shadows are not grey but a dull blue and that the snow in the sunshine is of a rich yellow. That artist's observational power is what is most wanted in the study of phenomenology. The second faculty we must strive to arm ourselves with is a resolute discrimination which fastens itself like a bulldog upon the particular feature that we are studying, follows it wherever it may lurk, and detects it beneath all its disguises. The third faculty we shall need is the generalizing power of the mathematician who produces the abstract formula that comprehends the very essence of the feature under examination purified from all admixture of extraneous and irrelevant accompaniments.
• Lecture II : The Universal Categories, § 1 : Presentness, CP 5.41 - 42
• When anything is present to the mind, what is the very first and simplest character to be noted in it, in every case, no matter how little elevated the object may be? Certainly, it is its presentness.
• Lecture II : The Universal Categories, § 1 : Presentness, CP 5.44
• The quality of feeling is the true psychical representative of the first category of the immediate as it is in its immediacy, of the present in its direct positive presentness. Qualities of feeling show myriad-fold variety, far beyond what the psychologists admit. This variety however is in them only insofar as they are compared and gathered into collections. But as they are in their presentness, each is sole and unique; and all the others are absolute nothingness to it — or rather much less than nothingness, for not even a recognition as absent things or as fictions is accorded to them. The first category, then, is Quality of Feeling, or whatever is such as it is positively and regardless of aught else.
• Lecture II : The Universal Categories, § 1 : Presentness, CP 5.44
• The next simplest feature that is common to all that comes before the mind, and consequently, the second category, is the element of Struggle.
• Lecture II : The Universal Categories, § 2 : Struggle, CP 5.45
• In all the works on pedagogy that ever I read — and they have been many, big, and heavy — I don't remember that any one has advocated a system of teaching by practical jokes, mostly cruel. That, however, describes the method of our great teacher, Experience. She says,
And I'll give you something to make you wise;
and thereupon she keeps her promise, and seems to take her pay in the fun of tormenting us.
• Lecture II : The Universal Categories, § 2 : Struggle, CP 5.51
• Understand me well. My appeal is to observation — observation that each of you must make for himself.
• Lecture II : The Universal Categories, § 2 : Struggle, CP 5.53
• Thus far, gentlemen, I have been insisting very strenuously upon what the most vulgar common sense has every disposition to assent to and only ingenious philosophers have been able to deceive themselves about. But now I come to a category which only a more refined form of common sense is prepared willingly to allow, the category which of the three is the chief burden of Hegel's song, a category toward which the studies of the new logico-mathematicians, Georg Cantor and the like, are steadily pointing, but to which no modern writer of any stripe, unless it be some obscure student like myself, has ever done anything approaching to justice.
• Lecture II : The Universal Categories, §3. Laws: Nominalism, CP 5.59
• There never was a sounder logical maxim of scientific procedure than Ockham's razor: Entia non sunt multiplicanda praeter necessitatem. That is to say; before you try a complicated hypothesis, you should make quite sure that no simplification of it will explain the facts equally well. No matter if it takes fifty generations of arduous experimentation to explode the simpler hypothesis, and no matter how incredible it may seem that that simpler hypothesis should suffice, still fifty generations are nothing in the life of science, which has all time before it; and in the long run, say in some thousands of generations, time will be economized by proceeding in an orderly manner, and by making it an invariable rule to try the simpler hypothesis first. Indeed, one can never be sure that the simpler hypothesis is not the true one, after all, until its cause has been fought out to the bitter end. But you will mark the limitation of my approval of Ockham's razor. It is a sound maxim of scientific procedure. If the question be what one ought to believe, the logic of the situation must take other factors into account. Speaking strictly, belief is out of place in pure theoretical science, which has nothing nearer to it than the establishment of doctrines, and only the provisional establishment of them, at that. Compared with living belief it is nothing but a ghost. If the captain of a vessel on a lee shore in a terrific storm finds himself in a critical position in which he must instantly either put his wheel to port acting on one hypothesis, or put his wheel to starboard acting on the contrary hypothesis, and his vessel will infallibly be dashed to pieces if he decides the question wrongly, Ockham's razor is not worth the stout belief of any common seaman. For stout belief may happen to save the ship, while Entia non sunt multiplicanda praeter necessitatem would be only a stupid way of spelling Shipwreck. Now in matters of real practical concern we are all in something like the situation of that sea-captain.
• Lecture II : The Universal Categories, §3. Laws: Nominalism, CP 5.60
• Philosophy, as I understand the word, is a positive theoretical science, and a science in an early stage of development. As such it has no more to do with belief than any other science. Indeed, I am bound to confess that it is at present in so unsettled a condition, that if the ordinary theorems of molecular physics and of archaeology are but the ghosts of beliefs, then to my mind, the doctrines of the philosophers are little better than the ghosts of ghosts. I know this is an extremely heretical opinion.
• Lecture II : The Universal Categories, §3. Laws: Nominalism, CP 5.61
• The third category of which I come now to speak is precisely that whose reality is denied by nominalism. For although nominalism is not credited with any extraordinarily lofty appreciation of the powers of the human soul, yet it attributes to it a power of originating a kind of ideas the like of which Omnipotence has failed to create as real objects, and those general conceptions which men will never cease to consider the glory of the human intellect must, according to any consistent nominalism, be entirely wanting in the mind of Deity.
• Lecture II : The Universal Categories, §3. Laws: Nominalism, CP 5.62
• All nature abounds in proofs of other influences than merely mechanical action, even in the physical world. They crowd in upon us at the rate of several every minute. And my observation of men has led me to this little generalization. Speaking only of men who really think for themselves and not of mere reporters, I have not found that it is the men whose lives are mostly passed within the four walls of a physical laboratory who are most inclined to be satisfied with a purely mechanical metaphysics. On the contrary, the more clearly they understand how physical forces work the more incredible it seems to them that such action should explain what happens out of doors. A larger proportion of materialists and agnostics is to be found among the thinking physiologists and other naturalists, and the largest proportion of all among those who derive their ideas of physical science from reading popular books.
• Lecture II : The Universal Categories, §3. Laws: Nominalism, CP 5.65

### A Neglected Argument for the Reality of God (1908)

"A Neglected Argument for the Reality of God" in the Hibbert Journal VII:90 (1908)
The third Universe comprises everything whose being consists in active power to establish connections between different objects, especially between objects in different Universes. Such is everything which is essentially a Sign...
The hypothesis of God is a peculiar one, in that it supposes an infinitely incomprehensible object, although every hypothesis, as such, supposes its object to be truly conceived in the hypothesis.
Unless man have a natural bent in accordance with nature's, he has no chance of understanding nature at all.
The humble argument is the first stage of a scientific inquiry into the origin of the three Universes, but of an inquiry which produces, not merely scientific belief, which is always provisional, but also a living, practical belief, logically justified in crossing the Rubicon with all the freightage of eternity.
• The word "God," so "capitalised" (as we Americans say), is the definable proper name, signifying Ens necessarium; in my belief Really creator of all three Universes of Experience.
• I, Ens necessarium is a latin expression which signifies "Necessary being, necessary entity"
• Some words shall herein be capitalised when used, not as vernacular, but as terms defined. Thus an "idea" is the substance of an actual unitary thought or fancy; but "Idea," nearer Plato's idea of ἰδέα, denotes anything whose Being consists in its mere capacity for getting fully represented, regardless of any person's faculty or impotence to represent it.
• I
• Of the three Universes of Experience familiar to us all, the first comprises all mere Ideas, those airy nothings to which the mind of poet, pure mathematician, or another might give local habitation and a name within that mind. Their very airy-nothingness, the fact that their Being consists in mere capability of getting thought, not in anybody's Actually thinking them, saves their Reality. The second Universe is that of the Brute Actuality of things and facts. I am confident that their Being consists in reactions against Brute forces, notwithstanding objections redoubtable until they are closely and fairly examined. The third Universe comprises everything whose being consists in active power to establish connections between different objects, especially between objects in different Universes. Such is everything which is essentially a Sign — not the mere body of the Sign, which is not essentially such, but, so to speak, the Sign's Soul, which has its Being in its power of serving as intermediary between its Object and a Mind.
• An "Argument" is any process of thought reasonably tending to produce a definite belief. An "Argumentation" is an Argument proceeding upon definitely formulated premisses.
If God Really be, and be benign, then, in view of the generally conceded truth that religion, were it but proved, would be a good outweighing all others, we should naturally expect that there would be some Argument for His Reality that should be obvious to all minds, high and low alike, that should earnestly strive to find the truth of the matter; and further, that this Argument should present its conclusion, not as a proposition of metaphysical theology, but in a form directly applicable to the conduct of life, and full of nutrition for man's highest growth. What I shall refer to as the N.A. — the Neglected Argument — seems to me best to fulfil this condition, and I should not wonder if the majority of those whose own reflections have harvested belief in God must bless the radiance of the N.A. for that wealth. Its persuasiveness is no less than extraordinary; while it is not unknown to anybody. Nevertheless, of all those theologians (within my little range of reading) who, with commendable assiduity, scrape together all the sound reasons they can find or concoct to prove the first proposition of theology, few mention this one, and they most briefly. They probably share those current notions of logic which recognise no other Arguments than Argumentations.
• The hypothesis of God is a peculiar one, in that it supposes an infinitely incomprehensible object, although every hypothesis, as such, supposes its object to be truly conceived in the hypothesis. This leaves the hypothesis but one way of understanding itself; namely, as vague yet as true so far as it is definite, and as continually tending to define itself more and more, and without limit. The hypothesis, being thus itself inevitably subject to the law of growth, appears in its vagueness to represent God as so, albeit this is directly contradicted in the hypothesis from its very first phase. But this apparent attribution of growth to God, since it is ineradicable from the hypothesis, cannot, according to the hypothesis, be flatly false. Its implications concerning the Universes will be maintained in the hypothesis, while its implications concerning God will be partly disavowed, and yet held to be less false than their denial would be. Thus the hypothesis will lead to our thinking of features of each Universe as purposed; and this will stand or fall with the hypothesis. Yet a purpose essentially involves growth, and so cannot be attributed to God. Still it will, according to the hypothesis, be less false to speak so than to represent God as purposeless.
• II
• Unless man have a natural bent in accordance with nature's, he has no chance of understanding nature at all.
• IV
• The difference between a pessimistic and an optimistic mind is of such controlling importance in regard to every intellectual function, and especially for the conduct of life, that it is out of the question to admit that both are normal, and the great majority of mankind are naturally optimistic.
• V
• The third argument, enclosing and defending the other two, consists in the development of those principles of logic according to which the humble argument is the first stage of a scientific inquiry into the origin of the three Universes, but of an inquiry which produces, not merely scientific belief, which is always provisional, but also a living, practical belief, logically justified in crossing the Rubicon with all the freightage of eternity.
• V
• My original essay, having been written for a popular monthly, assumes, for no better reason than that real inquiry cannot begin until a state of real doubt arises and ends as soon as Belief is attained, that "a settlement of Belief," or, in other words, a state of satisfaction, is all that Truth, or the aim of inquiry, consists in. The reason I gave for this was so flimsy, while the inference was so nearly the gist of Pragmaticism, that I must confess the argument of that essay might with some justice be said to beg the question. The first part of the essay, however, is occupied with showing that, if Truth consists in satisfaction, it cannot be any actual satisfaction, but must be the satisfaction which would ultimately be found if the inquiry were pushed to its ultimate and indefeasible issue. This, I beg to point out, is a very different position from that of Mr Schiller and the pragmatists of to-day. I trust I shall be believed when I say that it is only a desire to avoid being misunderstood in consequence of my relations with pragmatism, and by no means as arrogating any superior immunity from error which I have too good reason to know that I do not enjoy, that leads me to express my personal sentiments about their tenets. Their avowedly undefinable position, if it be not capable of logical characterisation, seems to me to be characterised by an angry hatred of strict logic, and even some disposition to rate any exact thought which interferes with their doctrines as all humbug. At the same time, it seems to me clear that their approximate acceptance of the Pragmaticist principle, and even that very casting aside of difficult distinctions (although I cannot approve of it), has helped them to a mightily clear discernment of some fundamental truths that other philosophers have seen but through a mist, and most of them not at all. Among such truths — all of them old, of course, yet acknowledged by few — I reckon their denial of necessitarianism; their rejection of any "consciousness" different from a visceral or other external sensation; their acknowledgment that there are, in a Pragmatistical sense, Real habits (which Really would produce effects, under circumstances that may not happen to get actualised, and are thus Real generals); and their insistence upon interpreting all hypostatic abstractions in terms of what they would or might (not actually will) come to in the concrete. It seems to me a pity they should allow a philosophy so instinct with life to become infected with seeds of death in such notions as that of the unreality of all ideas of infinity and that of the mutability of truth, and in such confusions of thought as that of active willing (willing to control thought, to doubt, and to weigh reasons) with willing not to exert the will (willing to believe).
• V

### Collected Papers (1931-1958)

The idea does not belong to the soul; it is the soul that belongs to the idea.
Mere imagination would indeed be mere trifling; only no imagination is mere.
• Do not block the way of inquiry.
• Vol. I, par. 135
• The idea does not belong to the soul; it is the soul that belongs to the idea.
• Vol. I, par. 216
• Effort supposes resistance.
• Vol. I, par. 320
• The ordinary logic has a great deal to say about genera and species, or in our nineteeth century dialect, about classes. Now a class is a set of objects compromising all that stand to one another in a special relation of similarity. But where ordinary logic talks of classes the logic of relatives talks of systems. A system is a set of objects compromising all that stands to one another in a group of connected relations. Induction according to ordinary logic rises from the contemplation of a sample of a class to that of a whole class; but according to the logic of relatives it rises from the comtemplation of a fragment of a system to the envisagement of the complete system.
• Vol. 3, par. 6
• Every man is fully satisfied that there is such a thing as truth, or he would not ask any question.
• Vol. V, par. 211
• To say, therefore, that thought cannot happen in an instant, but requires a time, is but another way of saying that every thought must be interpreted in another, or that all thought is in signs.
• Vol. V, par. 254
• Let us not pretend to doubt in philosophy what we do not doubt in our hearts.
• Vol. V, par. 265
• Consider what effects that might conceivably have practical bearings you conceive the objects of your conception to have. Then, your conception of those effects is the whole of your conception of the object.
• Vol. V, par. 438
• All the evolution we know of proceeds from the vague to the definite.
• Vol. VI, par. 191
• Mere imagination would indeed be mere trifling; only no imagination is mere.
• Vol. VI, par. 286
• Our whole past experience is continually in our consciousness, though most of it sunk to a great depth of dimness. I think of consciousness as a bottomless lake, whose waters seem transparent, yet into which we can clearly see but a little way.
• Vol. VII, par. 547

• Pierce wrote as a logician and James as a humanist.
• John Dewey, distinguishing the styles and focus of Peirce and William James, in The Development of American Pragmatism" in Studies in the History of Ideas (1925), Vol. II, p. 361
• Peirce was concerned to explicate the idea of meaning whereas James was concerned to explicate the meaning of ideas.
• Horace Standish Thayer, in his Introduction to a 1975 edition of Pragmatism by William James
• James called Peirce the most original thinker of their generation; Peirce placed himself somewhere near the rank of Leibniz. This much is now certain; he is the most original and versatile of America's philosophers and America's greatest logician.
• Peirce held that the continuity of space, time, ideation, feeling, and perception is an irreducible deliverance of science, and that an adequate conception of the continuous is an extremely important part of all the sciences. This doctrine he called “synechism,” a word deriving from the Greek preposition that means “(together) with.”