Next to Protagoras, the most famous Sophist was _Gorgias_. During the Peloponnesian war (426 B. C.), he came from Leontium to Athens in order to gain assistance for his native city against the encroachments of Syracuse, After the successful accomplishment of his errand he still abode for some time in Athens, but resided the latter part of his life in Thessaly, where he died about the same time with Socrates. The pompous ostentation of his external appearance is often ridiculed by Plato, and the discourses through which he was wont to exhibit himself display the same character, attempting, through poetical ornament, and florid metaphors, and uncommon words, and a mass of hitherto unheard of figures of speech, to dazzle and delude the mind. As a philosopher he adhered to the Eleatics, especially to Zeno, and attempts to prove upon the basis of their dialectic schematism, that universally nothing is, or if there could be a being, it would not be cognizable, or if cognizable it would not be communicable. Hence his writing bore characteristically enough the title—“_Concerning Not-being or Nature_.” The proof of the first proposition that universally nothing is, since it can be established neither as being nor as not-being, nor yet as at the same time both being and not-being, rests entirely upon the position that all existence is a space-filling existence (has place and body), and is in fact the final consequence which overturns itself, in other words the self-destruction of the hitherto physical method of philosophizing.