=The Prominent Sophists.= The list of Sophists is a long one. The first to call himself a Sophist and a teacher of public virtue was, according to Plato, Protagoras of Abdera. He was also probably the most eminent of the number. He was born about 480 B. C. Polus and Thrasymachus were the last; and Aristotle mentions the Sophists as in the past. So that we may conclude that as a band they existed only one hundred years (450–350 B. C.). Already at the beginning of the fourth century (400 B. C.) their importance had greatly diminished. In this hundred years we find some fourteen or fifteen prominent Sophists. There is, first, Protagoras, whose theory of knowledge is not only in itself a contribution to thought, but also of importance as a factor in forming the materialist atomistic doctrine of the school of Abdera,――the school of Leucippus and Democritus; Gorgias of Leontini, the head of an embassy to Athens, a man of eloquence, whose style was imitated by Thucydides and whom we might have studied in connection with the Eleatic school, for he carried out still further the doctrines of Zeno; Prodicus, the pupil of Protagoras and Gorgias, a brilliant man and a traveler, whose method of instruction was used by Socrates; Hippias, contemporary of Prodicus, remarkable for his mathematical, physical, and historical erudition, and a man full of vanity; the brothers, Euthydemus and Dionysiodorus, teachers of eristic; the rhetorician Thrasymachus and the rhetoricians of the school of Gorgias, viz., Polus, Lycophron, Protarchus, and Alcidamus; Evenus, rhetorician, moralist, and poet; Critias, the leader of the thirty; Callicles and Hippodamus. Many of these men were reformers. Some (as Alcidamus) were opposed to the institution of slavery in Greece; some to marriage; some (as Lycophron) to the nobility; some to the inequality of property; while Hippodamus was the first to propose an ideal state. The method of argumentation employed by the Sophists was first to perplex and confuse their opponents as to what had been taken in the past as valid. Then they made their opponents ridiculous by drawing out consequences from their statements. Their conclusions were often verbal and their witticisms vulgar.[16]