A theory of art is intended to contrast with a definition of art. Traditionally, definitions are composed of necessary and sufficient conditions and a single counterexample overthrows such a definition. Theorizing about art, on the other hand, is analogous to a theory of a natural phenomenon like gravity. In fact, the intent behind a theory of art is to treat art as a natural phenomenon that should be investigated like any other. The question of whether one can speak of a theory of art without employing a concept of art is also discussed below.

Art is a diverse range of human activity and its resulting product that involves creative or imaginative talent generally expressive of technical proficiency, beauty, emotional power, or conceptual ideas.