This Dialogue probably contains the first intimation of the doctrine of reminiscence and of the immortality of the soul.[2] The proof is very slight even slighter than in the Phaedo and Republic. Because men had abstract ideas in a previous state, they must have always had them, and their souls therefore must have always existed (86 A). For they must always have been either men or not men. The fallacy of the latter words is transparent. And Socrates himself appears to be conscious of their weakness; for he adds immediately afterwards, ‘I have said some things of which I am not altogether confident.’ (Cp. Phaedo 114 D, 115 D.) It may be observed, however, that the fanciful notion of pre-existence is combined with a true but partial view of the origin and unity of knowledge, and of the association of ideas. Knowledge is prior to any particular knowledge, and exists not in the previous state of the individual, but of the race. It is potential, not actual, and can only be appropriated by strenuous exertion. The idealism of Plato is here presented in a less developed form than in the Phaedo and Phaedrus. Nothing is said of the pre-existence of ideas of justice, temperance, and the like. Nor is Socrates positive of anything but the duty of enquiry (86 B). The doctrine of reminiscence too is explained more in accordance with fact and experience as arising out of the affinities of nature (ἅτε τῆς φύσεως ὅλης συγγενοῦς οὔσης). Modern philosophy says that all things in nature are dependent on one another; the ancient philosopher had the same truth latent in his mind when he affirmed that out of one thing all the rest may be recovered. The subjective was converted by him into an objective; the mental phenomenon of the association of ideas (cp. Phaedo 73 foll.) became a real chain of existences. The germs of two valuable principles of education may also be gathered from the ‘words of priests and priestesses:’ (1) that true knowledge is a knowledge of causes (cp. Aristotle’s theory of ἐπιστήμη); and (2) that the process of learning consists not in what is brought to the learner, but in what is drawn out of him.