Prabhat Ranjan Sarkar (May 21, 1921 – October 21, 1990), was an Indian philosopher, spiritual leader, social revolutionist, poet and linguist.
He contributed to the field of linguistics with his enormous works, including;
Sarkar, focuses on phonetics, morphology, dialectology, acoustics, syntax, etymology, grammar and semantics. He takes reference mainly of the Sanskrit and Bengali languages and further goes on dwelling on many other languages including English, French, Persian, Hindi, Urdu, German, Portuguese, Latin and others.
According to Sarkar, there are two forms of language; that is the language of the inner world or voice, which is only one and indivisible and the outer manifestation of the former, which is diverse. The former being rather a psychological concept, Sarkar focuses mainly on the latter one.
With his own words about what a language is;
"...In that fluidal flow of cognition, bubbles of ideas are created...when these bubbles touch the unit `I feeling', then unit ideas are created...When these ideas concern the unit, the unit `I' tries to express them through its own psycho-physical structure. It endeavours to express its unit desires and longings according to the capacity of the vocal chord and its hormone secretions. These reflections or refractions of ideas are expressed either within or without....These expressions within and without are collectively called language."
He sees the language as a means of expression and strongly emphasises that all languages, varieties, dialects and sub-dialects must be preserved and given the necessary importance. He also strongly criticises the political or nationalistic oppression of languages, done through declaring them as dialects or through other means.
There are no universally accepted criteria for distinguishing languages from dialects, although a number of paradigms exist, political, linguistic or a combination of both, which render most of the time contradictory results.
Depending on political realities and ideologies, the classification of speech varieties as dialects or languages and their relationship to other varieties of speech can be controversial and the verdicts inconsistent. English and Serbo-Croatian illustrate the point. English and Serbo-Croatian each have two major variants (British and American English, and Serbian and Croatian, respectively), along with numerous lesser varieties. For political reasons, analyzing these varieties as "languages" or "dialects" yields inconsistent results: British and American English, spoken by close political and military allies, are almost universally regarded as dialects of a single language, whereas the standard languages of Serbia and Croatia, which differ from each other to a similar extent as the dialects of English, are being treated by many linguists from the region as distinct languages, largely because the two countries oscillate from being brotherly to being bitter enemies.
The Yiddish linguist Max Weinreich published the expression, "A shprakh iz a dialekt mit an armey un flot" ("אַ שפראַך איז אַ דיאַלעקט מיט אַן אַרמײ און פֿלאָט", "A language is a dialect with an army and navy"; in Yivo-bleter 25.1, 1945, p. 13). It illustrates the fact that the political status of the speakers of a variety influences its perceived status as language or dialect. Most governments establish a standard variety of their language (or languages) to be taught in schools and used in official documents, courts and so on; often it is also promoted for use in the media.
Even lessening the impact of the political factors, language varieties are often called dialects rather than languages:
There are few non-political criteria for distinguishing languages from dialects, also named dialectological concepts. These are mainly:
Sarkar, approaching the question of "language or dialect", created eight main criteria for a language to be called a "language", and the rest "dialects". These criteria are strictly linguistic rather than political or cultural.
"Every language has its own special characteristics. It is these characteristics that set one language apart from another." 
According to Sarkar, no language or dialect should be subject to political or cultural exploitation, rather all languages, language varieties and dialects should be given full scope of expression in every arena of life. Their nomenclature (language, dialect, variant etc.) should be a hundred percent scientific, taking into consideration only linguistics, sociology and literature.
In his book, Varna Vijinana, he clearly states: "Roughly speaking there are eight conditions that must be fulfilled in order to be considered a language..." and further goes on explaining each of them.