(2) There is no hint in Plato's own writings that he was conscious of having made any change in the Doctrine of Ideas such as Dr. Jackson attributes to him, although in the Republic the platonic Socrates speaks of 'a longer and a shorter way', and of a way in which his disciple Glaucon 'will be unable to follow him'; also of a way of Ideas, to which he still holds fast, although it has often deserted him (Philebus, Phaedo), and although in the later dialogues and in the Laws the reference to Ideas disappears, and Mind claims her own (Phil.; Laws). No hint is given of what Plato meant by the 'longer way' (Rep.), or 'the way in which Glaucon was unable to follow'; or of the relation of Mind to the Ideas. It might be said with truth that the conception of the Idea predominates in the first half of the Dialogues, which, according to the order adopted in this work, ends with the Republic, the 'conception of Mind' and a way of speaking more in agreement with modern terminology, in the latter half. But there is no reason to suppose that Plato's theory, or, rather, his various theories, of the Ideas underwent any definite change during his period of authorship. They are substantially the same in the twelfth Book of the Laws as in the Meno and Phaedo; and since the Laws were written in the last decade of his life, there is no time to which this change of opinions can be ascribed. It is true that the theory of Ideas takes several different forms, not merely an earlier and a later one, in the various Dialogues. They are personal and impersonal, ideals and ideas, existing by participation or by imitation, one and many, in different parts of his writings or even in the same passage. They are the universal definitions of Socrates, and at the same time 'of more than mortal knowledge' (Rep.). But they are always the negations of sense, of matter, of generation, of the particular: they are always the subjects of knowledge and not of opinion; and they tend, not to diversity, but to unity. Other entities or intelligences are akin to them, but not the same with them, such as mind, measure, limit, eternity, essence (Philebus; Timaeus): these and similar terms appear to express the same truths from a different point of view, and to belong to the same sphere with them. But we are not justified, therefore, in attempting to identify them, any more than in wholly opposing them. The great oppositions of the sensible and intellectual, the unchangeable and the transient, in whatever form of words expressed, are always maintained in Plato. But the lesser logical distinctions, as we should call them, whether of ontology or predication, which troubled the pre-Socratic philosophy and came to the front in Aristotle, are variously discussed and explained. Thus far we admit inconsistency in Plato, but no further. He lived in an age before logic and system had wholly permeated language, and therefore we must not always expect to find in him systematic arrangement or logical