V. DISCUSSIONS. PLATO'S DOCTRINE OF IDEAS. BY the kindness of the Editor, I have permission to offer some remarks suggested by observations on Plato's Doctrine of Ideas made by Prof. Burnet in the course of a Review which appeared in a recent number of MIND (N.S., No. 57, pp. 94 ff.). I am glad to have this permission because it gives me the opportunity of ad- vancing a plea for the employment of Psychology to control con- clusions as to the meaning and scope of the Doctrine drawn by scholars from the literary data. The importance of this plea has been gradually brought home to me by my perusal of the expositions of the Doctrine offered by Prof. Henry Jackson and his followers, and by Dr. Lutoslawski. These expositions, however informing and suggestive they may be in parts, in themselves, as expositions, seem to me to fall short of scientific sufficiency because not controlled from the basis of Psy- chology. The literary evidence contained in Plato's Dialogues and Aristotle's Criticisms is fully taken, but submitted to the judg- ment of no court. The cardinal question is not asked : What has present-day Psychology to tell us about the Variety of Experience which expresses itself in the Doctrine of Ideas? The Doctrine is treated as if it were a ' past event ' in the ' History of Philosophy ' for determining the true nature of which there is such and such documentary evidence which, if only marshalled in the right way, is, in itself, conclusive. It is as if a commentator on Thucydides should think it unnecessary to submit the literary record of the Plague at Athens to the judgment of present-day medical science in order to ascertain from that authority what precisely the disease is which his author is endeavouring to describe. The fault, then, that I have to find with the expositors whom I have mentioned is that they think it unnecessary to ask the ques- tion : What has modern Psychology to tell us about the Variety of Experience which finds expression in the Doctrine of Ideas? They go to the text in the dark. They converge on no generally acceptable, no obviously correct, view of its purport. With confus- ing variety of detail they tell us that, at one period of his career, Plato held this opinion, and, at another period, that opinion, while Pupils of the Academy, Pythagoreans, Eleatics, Megarics, not to mention Aristotle himself, held certain other opinions about the
