when it has actually been achieved by nature in the particular case. This anticipation is the _Ideal_. It is the _Idea_ so far as it is known _a priori_, at least half, and it becomes practical for art, because it corresponds to and completes what is given _a posteriori_ through nature. The possibility of such an anticipation of the beautiful _a priori_ in the artist, and of its recognition _a posteriori_ by the critic, lies in the fact that the artist and the critic are themselves the “in-itself” of nature, the will which objectifies itself. For, as Empedocles said, like can only be known by like: only nature can understand itself: only nature can fathom itself: but only spirit also can understand spirit.(54) The opinion, which is absurd, although expressed by the Socrates of Xenophon (Stobæi Floril, vol. ii. p. 384) that the Greeks discovered the established ideal of human beauty empirically, by collecting particular beautiful parts, uncovering and noting here a knee, there an arm, has an exact parallel in the art of poetry. The view is entertained, that Shakespeare, for example, observed, and then gave forth from his own experience of life, the innumerable variety of the characters in his dramas, so true, so sustained, so profoundly worked out. The impossibility and absurdity of such an assumption need not be dwelt upon. It is obvious that the man of genius produces the works of poetic art by means of an anticipation of what is characteristic, just as he produces the works of plastic and pictorial art by means of a prophetic anticipation of the beautiful; yet both require experience as a pattern or model, for thus alone can that which is dimly known _a priori_ be called into clear consciousness, and an intelligent representation of it becomes possible.