History of Western Philosophy - Bertrand Russell [77]
In the first place, Plato has no understanding of philosophical syntax. I can say 'Socrates is human', 'Plato is human', and so on. In all these statements, it may be assumed that the word 'human' has exactly the same meaning. But whatever it means, it means something which is not of the same kind as Socrates, Plato, and the rest of the individuals who compose the human race. 'Human' is an adjective; it would be nonsense to say 'human is human'. Plato makes a mistake analogous to saying 'human is human'. He thinks that beauty is beautiful; he thinks that the universal 'man' is the name of a pattern man created by God, of whom actual men are imperfect and somewhat unreal copies. He fails altogether to realize how great is the gap between universals and particulars; his 'ideas' are really just other particulars, ethically and aesthetically superior to the ordinary kind. He himself, at a later date, began to see this difficulty, as appears in the Parmenides, which contains one of the most remarkable cases in history of self-criticism by a philosopher.
The Parmenides is supposed to be related by Antiphon (Plato's half-brother), who alone remembers the conversation, but is now only interested in horses. They find him carrying a bridle, and with difficulty persuade him to relate the famous discussion between Parmenides, Zeno, and Socrates. This, we are told, took place when Parmenides was old (about sixty-five), Zeno in middle life (about forty), and Socrates quite a young man. Socrates expounds the theory of ideas; he is sure that there are ideas of likeness, justice, beauty, and goodness; he is not sure that there is an idea of man; and he rejects with indignation the suggestion that there could be ideas of such things as hair and mud and dirt—though, he adds, there are times when he thinks that there is nothing without an idea. He runs away from this view because he is afraid of falling into a bottomless pit of nonsense.
'Yes, Socrates, said Parmenides; that is because you are still young; the time will come, if I am not mistaken, when philosophy will have a firmer grasp of you, and then you will not despise even the meanest things.'
Socrates agrees that, in his view, 'There are certain ideas of which all other things partake, and from which they derive their names; that similars, for example, become similar, because they partake of similarity; and great things become great, because they partake of greatness; and that just and beautiful things become just and beautiful, because they partake of justice and beauty.'
Parmenides proceeds to raise difficulties. (a) Does the individual partake of the whole idea, or only of a part? To either view there are objections. If the former, one thing is in many places at once; if the latter, the idea is divisible, and a thing which has a part of smallness will be smaller than absolute smallness, which is absurd. (b) When an individual partakes of an idea, the individual and the idea are similar; therefore there will have to be another idea, embracing both the particulars and the original idea. And there will have to be yet another, embracing the particulars and the two ideas, and so on ad infinitum. Thus every idea, instead of being one, becomes an infinited series of ideas. (This is the same as Aristotle's argument of the 'third man'.) (c) Socrates suggests that perhaps ideas are only thoughts; but Parmenides points out that thoughts must be of something. (d) Ideas cannot resemble the particulars that partake of them, for the reason given in (b) above. (e) Ideas, if there are any, must be unknown to us, because our knowledge is not absolute. (f) If God's knowledge