In voting theory, nondictatorship is the property that in social choice functions, the results should not and must not simply mirror that of any ONE single person's preferences without consideration of the other voters. Fairness requires that the social welfare function take into account the desires of more than one voter. In other words, there is no one voter with P as his/her individual preference order, such that P is the societal ("winning") preference order, unless all voters have the same P. Thus, as long as there are voters in the society that have different preference orderings, individual is' preferences should not always prevail.
Nondictatorship: No voter in the society is a dictator in the sense that, there does not exist a single voter i in the society such that for every set of orderings in the domain and every pair of distinct social states x and y, if voter i strictly prefers x over y, x is socially selected over y.
There is no voter i in {1, ..., n} such that for every set of orderings in the domain of the constitution and every pair of social states x and y, x P_{i} y implies x P y. 
Anonymous voting systems (with at least two voters) automatically satisfy the nondictatorship property.
