2. THE SOUL.—The doctrine of the soul, considering it simply as the basis of a moral action, and leaving out of view all questions of concrete ethics, forms a constituent element in the Platonic physics. Since the soul is united to the body, it participates in the motions and changes of the body, and is, in this respect, related to the perishable. But in so far as it participates in the knowledge of the eternal, _i. e._ in so far as it knows ideas, does there live within it a divine principle—reason. Accordingly, Plato distinguishes two components of the soul—the divine and the mortal, the rational and the irrational. These two are united by an intermediate link, which Plato calls θυμὸς or spirit, and which, though allied to reason is not reason itself, since it is often exhibited in children and also in brutes, and since even men are often carried away by it without reflection. This threefoldness, here exhibited psychologically, is found, in different applications, through all the last general period of Plato’s literary life. Based upon the anthropological triplicate of reason, soul and body, it corresponds also to the division of theoretical knowledge into science (or thinking), correct opinions (or sense-perception), and ignorance, to the triple ladder of eroticism in the Symposium and the mythological representation connected with this of Poros, Eros, and Penia; to the metaphysical triplicate of the ideal world, mathematical relations and the sensible world; and furnishes ground for deriving the ethical division of virtue and the political division of ranks.