We cannot here dwell upon the aesthetic theories of men of letters, such as that of E. Zola, developing his thesis of natural science and history mixed, which is known as that of the human document or as the experimental theory, or of Ibsen and the moralization of the art problem, as presented by him and by the Scandinavian school. Perhaps no French writer has written more profoundly upon art than Gustave Flaubert. His views are contained in his Correspondence, which has been published. L. Tolstoï wrote his book on art while under the influence of Véron and his hatred of the concept of the beautiful. Art, he says, communicates the feelings, as the word communicates the thoughts. But his way of understanding this may be judged from the comparison which he institutes between Art and Science. According to this, "Art has for its mission to make assimilable and sensible what may not have been assimilated in the form of argument. There is no science for science's sake, no art for art's sake. Every human effort should be directed toward increasing morality and suppressing violence." This amounts to saying that well-nigh all the art that the world has hitherto seen is false. Aeschylus, Sophocles, Euripides, Aristophanes, Dante, Tasso, Milton, Shakespeare, Raphael, Michael Angelo, Bach, Beethoven, are all, according to Tolstoï, "false reputations, made by the critics." We must also class F. Nietzsche with the artists, rather than with the philosophers. We should do him an injustice (as with J. Ruskin) were we to express in intellectual terminology his aesthetic affirmations. The criticism which they provoke would be too facile. Nowhere has Nietzsche given a complete theory of art, not even in his first book, _Die Geburt der Tragödie oder Griechentum und Pessimismus_. What seems to be theory there, is really the confession of the feelings and aspirations of the writer. Nietzsche was the last, splendid representative of the romantic period. He was, therefore, deeply preoccupied with the art problem and with the relation of art to natural science and to philosophy, though he never succeeded in definitely fixing those relations. From Romanticism, rather than from Schopenhauer, he gathered those elements of thought out of which he wove his conception of the two forms of art: the Apollonian, all serene contemplation, as expressed in the epic and in sculpture; the Dionysaïc, all tumult and agitation, as expressed in music and the drama. These doctrines are not rigorously proved, and their power of resistance to criticism is therefore but slender, but they serve to transport the mind to a more lofty spiritual level than any others of the second half of the nineteenth century.