r The Sophists. 181 are established and exist vopa, "by convention/' dXX' ov $vaei t As examples of this connection between their theory and prac- tice the following instances are cited, Xen. Mem. iv. 4. 14. 20, where Hippias contests the truth of a moral principle by the observation, that it is not universally received; and argues against laws in general and the obligation to obey them on the ground that they are liable to be changed at any moment : again Protag. 337. d. where he is made to say that the law is a tyrant which forces us to do many things contrary to nature. That laws are a mere convention is a sentiment put into the mouth of Protagoras, Theset. 167. c. [in a passage in which his views are represented in the most favourable light, and where therefore no exaggeration can be suspected], and especially con- nected with his theory of knowledge, " whatsoever seems to each city just and right, to her this is so, so long as she sanctions it." So Thrasymachus, Rep. i. 338. c. sq. maintains that right is nothing but the interest of the stronger, and in every state the rulers make laws for their own advantage. And Callicles, the pupil of the Sophists, Gorg. 482, sq. insisting on the distinction of cf>v<n S and vofios lays down a similar doctrine. We cannot however suppose, continues Zeller, that all these doctrines were main- tained by all the Sophists, but a like spirit led to similar results in all. All the passages here referred to, together with others not adduced by Zeller, have been already brought forward. They seem to prove that Protagoras' doctrine in its spirit, if not in the letter, was common at least to several of the class; together with a certain practical, and in most of them theoretical, scep- ticism; which they expressed as Plato and Aristotle distinctly tell us by the opposition of things existing fyvo-ei and vo^to (see de Legg. de Soph. El. 11. cc.) : further they were all alike distin- guished by a similar method of reasoning, and by a similar system of instruction based upon similar principles, though per- haps not comprising in all cases the same doctrines, and tending to a like result. Moreover they had certain common character- istics personal and professional with which we are not here immediately concerned. All this is doubtless not enough to constitute them a " doctrinal sect" or philosophical school ; but neither is it fair to say on the other hand that they had abso- lutely no doctrines principles or method in common : and it
