But to understand Plato's conception of the progression of experience we must again catch up the Socratic strain which he weaves into every theme. For Socrates, student of life and mankind, all objects were objects of interest, and all interests practical interests. One is ignorant when one does not know the good of things; opinionative when one rates things by conventional standards; wise when one knows their real good. In Platonism this practical interpretation of experience appears in the principle that the object of perfect knowledge is _the good_. The nature of things which one seeks to know better is the good of things, the absolute being which is the goal of all thinking is the very good itself. Plato does not use the term good in any merely utilitarian sense. Indeed it is very significant that for Plato there is no cleavage between theoretical and practical interests. To be morally good is to know the good, to set one's heart on the true object of affection; and to be theoretically sound is to understand perfection. The good itself is the end of every aim, that in which all interests converge. Hence it cannot be defined, as might a special good, in terms of the fulfilment of a set of concrete conditions, but only in terms of the sense or direction of all purposes. The following passage occurs in the "Symposium": "The true order of going or being led by others to the things of love, is to use the beauties of earth as steps along which he mounts upward for the sake of that other beauty, going from one to two, and from two to all fair forms, and from fair forms to fair actions, and from fair actions to fair notions, until from fair notions he arrives at the notion of absolute beauty, and at last knows what the essence of beauty is."[329:8] [Sidenote: The Progression of Experience toward God.]