The question of the nature of art, what art is, has been much more widely discussed in philosophy than the question of its value, why art matters. The two issues cannot be completely disentangled, of course, since any account of what makes art art will inevitably isolate features of special importance. In fact, all the main theories of the nature of art have an implicit explanation of its value, but since the question of the value of art has social as well as philosophical significance, it is useful to make these implicit accounts explicit, and thus expose them to critical scrutiny.

Four lines of thought have emerged as the principal ways in which philosophers and artists have explained the importance of art. These can be given convenient labels: hedonism, aestheticism, expressionism, and cognitivism. Briefly, the first holds that art is valuable for the pleasure...