The refutation seems tolerably complete, but a good deal had to happen before Greece was ready to accept or Plato to offer such a refutation.
_Nothing knowable--The solitude of scepticism--The lawlessness of scepticism--The good in scepticism_
Gorgias was perhaps even more eminent a Sophist than Protagoras. He was a native of Leontini in Sicily, and came to Athens in the year 427 B.C. on a public embassy from his native city. The splendid reputation for political and rhetorical ability, which preceded him to Athens, he fully justified both by his public appearances before the Athenian assembly, and by the success of his private instructions to the crowds of wealthy young men who resorted to him. He dressed in magnificent style, and affected a lofty and poetical manner of speech, which offended the more critical, but which pleased the crowd.
He also, like Protagoras, published a treatise in which he expounded his fundamental principles, and like Protagoras, he preceded it with a striking if somewhat ironical title, and an apophthegm in which he summarised his doctrine. The title of his work was _Of the Non-Existent_, that is, _Of Nature_, and { 93} his dictum, "Nothing exists, or if anything exists, it cannot be apprehended by man, and even if it could be apprehended, the man who apprehended it could not expound or explain it to his neighbour." In support of this strange doctrine, Gorgias adopted the quibbling method of argument which had been applied with some success to dialectical purposes by Zeno, Melissus, and others (see above, pp. 44 _sqq._)
His chief argument to prove the first position laid down by him depended on a double and ambiguous use of the word _is_; "That which is not, _is_ the non-existent: the word _is_ must, therefore, be applicable to it as truly as when we say That which is, _is_; therefore, being is predicable of that which is not." So conversely he proved not-being to be predicable of that which is. And in like manner he made away with any possible assertions as to the finite or infinite, the eternal or created, nature of that which is. Logic could supply him with alternative arguments from whatever point he started, such as would seem to land the question in absurdity. Hence his first position was (he claimed) established, that 'Nothing is.'