[185]
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.'
To prove the second, that even if anything is, it cannot be known to man, he argued thus: "If what a man thinks is not identical with what is, plainly what is cannot be thought. And that what a man thinks is not identical with what is can be {94} shown from the fact that thinking does not affect the facts. You may imagine a man flying, or a chariot coursing over the deep, but you do not find these things to occur because you imagine them. Again, if we assume that what we think is identical with what is, then it must be impossible to think of what is not. But this is absurd; for we can think of such admittedly imaginary beings as Scylla and Chimaera, and multitudes of others. There is therefore no necessary relation between our thoughts and any realities; we may believe, but we cannot prove, which (if any) of our conceptions have relation to an external fact and which have not."
[187]
Nor thirdly, supposing any man had obtained an apprehension of what is real, could he possibly communicate it to any one else. If a man saw anything, he could not possibly by verbal description make clear what it is he sees to a man who has never seen. And so if a man has not himself the apprehension of reality, mere words from another cannot possibly give him any idea of it. He may imagine he has the same idea as the speaker, but where is he going to get the common test by which to establish the identity?
Without attempting to follow Gorgias further, we can see plainly enough the object and purport of the whole doctrine. Its main result is to isolate. It isolates each man from his fellows; he cannot tell {95} what they know or think, they cannot reach any common ground with him. It isolates him from nature; he cannot tell what nature is, he cannot tell whether he knows anything of nature or reality at all. It isolates him from himself; he cannot tell for certain what relation exists (if any) between what he imagines he perceives at any moment and any remembered or imagined previous experiences; he cannot be sure that there ever were any such experiences, or what that self was (if anything) which had them, or whether there was or is any self perceiving anything.
Let us imagine the moral effect on the minds of the ablest youth of Greece of such an absolute collapse of belief. The philosophic scepticism did not deprive them of their appetites or passions; it did not in the least alter their estimate of the prizes of success, or the desirability of wealth and power. All it did was to shatter the invisible social bonds of reverence and honour and truth and justice, which in greater or less degree act as a restraining force upon the purely selfish appetites of men. Not only belief in divine government disappeared, but belief in any government external or internal; justice became a cheating device to deprive a man of what was ready to his grasp; good-faith was stupidity when it was not a more subtle form of deceit; morality was at best a mere convention which a man might cancel if {96} he pleased; the one reality was the appetite of the moment, the one thing needful its gratification; society, therefore, was universal war, only with subtler weapons.
Of course Protagoras and Gorgias were only notable types of a whole horde of able men who in various ways, and with probably less clear notions than these men of the drift or philosophic significance of their activity, helped all over Greece in the promulgation of this new gospel of self-interest. Many Sophists no doubt troubled themselves very little with philosophical questions; they were 'agnostics,' know-nothings; all they professed to do was to teach some practical skill of a verbal or rhetorical character. They had nothing to do with the nature or value of ideals; they did not profess to say whether any end or aim was in itself good or bad, but given an end or aim, they were prepared to help those who hired them to acquire a skill which would be useful towards attaining it.
But whether a philosophy or ultimate theory of life be expressly stated or realised by a nation or an individual, or be simply ignored by them, there always is some such philosophy or theory underlying their action, and that philosophy or theory tends to work itself out to its logical issue in action, whether men openly profess it or no. And the theory of negation of law in nature or in man which underlay {97} the sophistic practice had its logical and necessary effect on the social structure throughout Greece, in a loosening of the bonds of religion, of family reverence and affection, of patriotism, of law, of honour. Thucydides in a well-known passage (iii. 82) thus describes the prevalent condition of thought in his own time, which was distinctively that of the sophistic teaching: "The common meaning of words was turned about at men's pleasure; the most reckless bravo was deemed the most desirable friend; a man of prudence and moderation was styled a coward; a man who listened to reason was a good-for-nothing simpleton. People were trusted exactly in proportion to their violence and unscrupulousness, and no one was so popular as the successful conspirator, except perhaps one who had been clever enough to outwit him at his own trade, but any one who honestly attempted to remove the causes of such treacheries was considered a traitor to his party. As for oaths, no one imagined they were to be kept a moment longer than occasion required; it was, in fact, an added pleasure to destroy your enemy if you had managed to catch him through his trusting to your word."
These are the words not of Plato, who is supposed often enough to allow his imagination to carry him beyond his facts about the Sophists as about others, nor are they the words of a satiric poet such as {98} Aristophanes. They are the words of the most sober and philosophic of Greek historians, and they illustrate very strikingly the tendency, nay, the absolute necessity, whereby the theories of philosophers in the closet extend themselves into the market-place and the home, and find an ultimate realisation of themselves for good or for evil in the 'business and bosoms' of the common crowd.