In this little book I have tried to develop a complete theory of visual art. I have put forward an hypothesis by reference to which the respectability, though not the validity, of all aesthetic judgments can be tested, in the light of which the history of art from palaeolithic days to the present becomes intelligible, by adopting which we give intellectual backing to an almost universal and immemorial conviction. Everyone in his heart believes that there is a real distinction between works of art and all other objects; this belief my hypothesis justifies.