Sophists, primarily professional teachers of rhetoric and other branches of learning in Greece in the latter part of the 5th cent. B.C. Professing as they did to teach the newest learning, they (or rather some of the most conspicuous of them) came to appear as a kind of sect or school of philosophers representing and intensifying the sceptical tendencies of the time. The earlier Sophists were declamatory and rhetorical: the later perhaps imitated Socrates' dialectic. They were renowned for their power in rhetoric and grammar, both of which subjects they taught for pay. Much of what we know of them is derived from Plato and Aristotle, who judged them by a somewhat transcendental standard. Protagoras, Gorgias, and Prodicus were among the leading Sophists.