TWO:The Alexandrian Sceptics general arguments against the possibility of knowledge resolve themselves into a criticism of what Sir W. Hamilton called Natural Realism, somewhat complicated and confused by a simultaneous attack on the theory of natural morality conceived as something eternal and immutable. They are summed up in the famous ten Tropes. Of these the first three are founded on the conflicting sensations produced by the same object when acting on different animalsas is inferred from the marked contrast presented by their several varieties of origin and structure,on different men, and on the different senses of the same individual. The fourth, which has evidently an ethical bearing, enlarges on the changes in mens views caused by mental and bodily changes, according to their health, age, disposition, and so forth. The next five Tropes relate to circumstances connected with the objects themselves: their distance and position as regards the spectator, the disturbance produced in their proper action by external influences such as air and light, together with the various membranes and humours composing the organs of sense through which they are apprehended; their quantitative variation, involving as it does opposite effects on the senses, or as with medicines, on the health; the law of relativity, according to which many things are only known when taken in company with others, such as double and half, right and left, whole and part; comparative frequency or rarity of occurrence, as with comets, which, while really of much less importance than the sun, excite much more interest from their being so seldom seen. Finally, the tenth Trope is purely ethical, and infers the non-existence of a fixed moral standard from the divergent and even opposite customs prevailing among different nations.297From utter confusion to extreme nihilism there was but a single step. This step was taken by Gorgias, the Sicilian rhetorician, who held the same relation towards western Hellas and the Eleatic school as that which Protagoras held towards eastern Hellas and the philosophy of Heracleitus. He, like his eminent contemporary, was opposed to the thinkers whom, borrowing a useful term from the nomenclature of the last century, we may call the Greek physiocrats. To confute them, he wrote a book with the significant title, On Nature or Nothing: maintaining, first, that nothing exists; secondly, that if anything exists, we cannot know it; thirdly, that if we know it, there is no possibility of communicating our knowledge to others. The first thesis was established by pushing the Eleatic arguments against movement and change a little further; the second by showing that thought and existence are different, or else everything that is thought of would exist; the third by establishing a similar incommensurability between words and sensations. Grote96 has attempted to show that Gorgias was only arguing against the existence of a noumenon underlying phenomena, such as all idealists deny. Zeller has, however, convincingly proved that Gorgias, in common with every other thinker before Plato, was ignorant of this distinction;72 and we may add that it would leave the second and third theses absolutely unimpaired. We must take the whole together as constituting a declaration of war against science, an assertion, in still stronger language, of the agnosticism taught by Protagoras. The truth is, that a Greek controversialist generally overproved his case, and in order to overwhelm an adversary pulled down the whole house, even at the risk of being buried among the ruins himself. A modern reasoner, taking his cue from Gorgias, without pushing the matter to such an extreme, might carry on his attack on lines running parallel with those laid down by the Sicilian Sophist. He would begin by denying the existence of a state of Nature; for such a state must be either variable or constant. If it is constant, how could civilisation ever have arisen? If it is variable, what becomes of the fixed standard appealed to? Then, again, supposing such a state ever to have existed, how could authentic information about it have come down to us through the ages of corruption which are supposed to have intervened? And, lastly, granting that a state of Nature accessible to enquiry has ever existed, how can we reorganise society on the basis of such discordant data as are presented to us by the physiocrats, no two of whom agree with regard to the first principles of natural order; one saying that it is equality, another aristocracy, and a third despotism? We do not say that these arguments are conclusive, we only mean that in relation to modern thought they very fairly represent the dialectic artillery brought to bear by Greek humanism against its naturalistic opponents.
