information:classification
Sophism

Sophism arose from the juxtaposition of physis (nature) and nomos (law). John Burnet posits its origin in the scientific progress of the previous centuries which suggested that Being was radically different from what was experienced by the senses and, if comprehensible at all, was not comprehensible in terms of order; the world in which people lived, on the other hand, was one of law and order, albeit of humankind's own making. At the same time, nature was constant, while what was by law differed from one place to another and could be changed.

The first person to call themselves a sophist, according to Plato, was Protagoras, whom he presents as teaching that all virtue is conventional. It was Protagoras who claimed that "man is the measure of all things, of the things that are, that they are, and of the things that are not, that they are not," which Plato interprets as a radical perspectivism, where some things seem to be one way for one person (and so actually are that way) and another way for another person (and so actually are that way as well); the conclusion being that one cannot look to nature for guidance regarding how to live one's life.

Protagoras and subsequent sophists tended to teach rhetoric as their primary vocation. Prodicus, Gorgias, Hippias, and Thrasymachus appear in various dialogues, sometimes explicitly teaching that while nature provides no ethical guidance, the guidance that the laws provide is worthless, or that nature favors those who act against the laws.