Dr WHEWELL, on the PLATONIC THEORY OF IDEAS. 97 



This I conceive to be the simplest and directest ground of two primary parts of the 

 Theory of Ideas; — The Eternal Ideas constituting an Intelligible World; and the Partici- 

 pation in these Ideas ascribed to the objects of the world of sense. And it is plain that so far, 

 the Theory meets what, I conceive, was its primary purpose; it answers the questions, How 

 can we have certain knowledge, though we cannot get it from Sense ? and, How can we have 

 knowledge, at least apparent, though imperfect, about the world of sense ? 



But is this the ground on which Plato himself rests the truth of his Theory of Ideas ? 

 As I have said, I have no doubt that these were the questions which suggested the Theory; 

 and it is perpetually applied in such a manner as to shew that it was held by Plato in this 

 sense. But his applications of the Theory refer very often to another part of it; — to the 

 Ideas, not of Triangles and Squares, of space and its affections; but to the Ideas of Relations — 

 as the Relations of Like and Unlike, Greater and Less; or to things quite different from 

 the things of which geometry treats, for instance, to Tables and Chairs, and other matters, 

 with regard to which no demonstration is possible, and no general truth (still less necessary 

 and eternal truth) capable of being asserted. 



I conceive that the Theory of Ideas, thus asserted and thus supported, stands upon very 

 much weaker ground than it does, when it is asserted concerning the objects of thought, 

 about which necessary and demonstrable truths are attainable. And in order to devise argu- 

 ments against this part of the Theory, and to trace the contradictions to which it leads, we 

 have no occasion to task our own ingenuity. We find it done to our hands, not only in 

 Aristotle, the open opponent of the Theory of Ideas, but in works which stand among the 

 Platonic Dialogues themselves. And I wish especially to point out some of the arguments 

 against the Ideal Theory, which are given in one of the most noted of the Platonic Dialogues, 

 the Parmenides. 



The Parmenides contains a narrative of a Dialogue held between Parmenides and Zeno, 

 the Eleatic Philosophers, on the one side, and Socrates, along with several other persons, on 

 the other. It may be regarded as divided into two main portions ; the first, in which the 

 Theory of Ideas is attacked by Parmenides, and defended by Socrates ; the second, in which 

 Parmenides discusses, at length, the Eleatic doctrine that All things are One. It is the 

 former part, the discussion of the Theory of Ideas, to which I especially wish to direct 

 attention at present : and in the first place, to that extension of the Theory of Ideas, to 

 things of which no general truth is possible ; such as I have mentioned, tables and chairs. 

 Plato often speaks of a Table, by way of example, as a thing of which there must be an 

 Idea, not taken from any special Table or assemblage of Tables ; but an Ideal Table, such that 

 all Tables are Tables by participating in the nature of this Idea. Now the question is, 

 whether there is any force, or indeed any sense, in this assumption ; and this question is 

 discussed in the Parmenides. Socrates is there represented as very confident in the existence 

 of Ideas of the highest and largest kind, the Just, the Fair, the Good, and the like. 

 Parmenides asks him how far he follows his theory. Is there, he asks, an Idea of Man, which 

 is distinct from us men ? an Idea of Fire.'' of Water ? " In truth," replies Socrates, " I have 

 often hesitated, Parmenides, about these, whether we are to allow such Ideas." When 

 Plato had proceeded to teach that there is an Idea of a Table, of course he could not reject 

 Vol. X. Part I. 13 



