There are still further sources of art. After having been successful in his struggle, when he has some leisure, man observes that many things which he uses as weapons, as tools, for food, and so on, are capable of giving him pleasure quite aside from their practical significance. He therefore obtains these things for their own sake. He collects brilliantly colored feathers, glittering stones and pearls. The instinctive reactions upon pleasant experiences are discovered to be pleasant themselves. They are voluntarily repeated. Thus dance and song originate. In a similar manner, from the descriptions of ordinary life, tales takes their origin. Symmetry and rhythm are discovered and become of the greatest importance for the various arts. In spite of the manifoldness of its origin and its application, we may speak of art in the singular, because all the different arts have this in common, that they give joy without serving any conscious purpose. In every art three factors may be distinguished on which the feeling aroused in us depends: the subject-matter or content, the form, and the personal significance. If the work of art is a picture, it may represent a battle or a landscape; if a poem, the wanderings of Ulysses or the story of the Erlking; if music, a waltz or a funeral march. This subject-matter is given a particular form or structure. The twelve disciples of the Last Supper may be placed in a simple row or arranged in groups of various kinds. A church may be built in Roman or Gothic style. Meter and rhyme differ in various poems. Music may be harmonized in many different ways. All this refers to the form of art. The third factor, the personal significance, may be illustrated by the different moods which speak to us from pictures of the same subject-matter and similar form, also by the technique chosen by the painter. The picture may appear to me as an assembly of Jewish fishermen or as an historical act in which the disciples of the Lord and he himself take part. Much could be said about all this in detail. Some important insight into the relation of the different factors can be obtained from a discussion of the first one, the subject-matter. How does the artist succeed in giving us, through his subject-matter, pleasure independent of and free from any consciousness of purpose? Two ways are open to him. The first appears most clearly in music. It consists in using contents which play no part in the world of needs. Musical tones, sung or produced by instruments, do not contribute to the preservation of man; and therefore they do not incite our desire. However, when properly combined, they are capable of arousing the most varied and intense feelings, moods, emotions. They are thus especially adapted to serve as material, as contents, of a work of art.