Now, apparently, we are at the beginning of a new movement, a return to imaginative art, and the evidences of this return are seen not only in painting but in decoration, in sculpture, in music, in drama, in literature, in fiction, in philosophy, in medicine, in business, in politics. _There is a demand_ for _ideals_ as distinguished from _results_. * * * * * We have learned that the proper end of poetry is the expression of emotion, to which all reasoning and statement of fact should be subsidiary; but we have not learned that painting should have the same end, using representation only as a means to that end, and representing only those facts of reality which have emotional associations for the painter. In primitive pictures, it is true, we look for the expression of emotion rather than for illusion, and that is the reason why so many people get a real pleasure from primitive art. They judge it by the right standard, and ask of it what it offers to them. But from modern pictures they demand illusion--that is to say, the kind of representation they are used to; and when they do not get it they accuse the artist of incompetence.[15] * * * * * In painting this reaction, this tendency--call it what you please--has taken many forms, one of which is _Cubism_. While this book devotes much space to Cubism, it is solely because in its extreme development it is, from a coldly critical point of view, the _most abstract_ word yet uttered in painting, it is the farthest removed from impressionism, and therefore serves admirably to illustrate a discussion of the philosophy of _Post-Impressionism_. In a book like this, written as an off-hand comment upon what is now going on in the world of art--in the world generally, for that matter--it would be quite impracticable to follow the development of even the principal lines of human activity;[16] hence the works and theories of the Cubists have been chosen as typical of radical and revolutionary ideas and the attempt is made to find wherein these works and ideas are not so radical and extravagant as they seem, but are, in fact, only an illustration of what is going on in the minds of men generally. If the painter who laughs at a Cubist painting and denounces it will only stop to think he will find one of two things true, he himself is either advancing in his art or he is not. If he is not, there is nothing further to be said, his attitude toward the Cubist painting is quite consistent; but if he is advancing, if his style, his technic, his point of view are changing, _however slightly_, from year to year, then he should be exceedingly cautious how he ridicules or condemns, for without knowing it he may be traveling the highroad, one of the interesting byways of which is Cubism.