Berkeley's idealism started a revolution in philosophy. As one of the great empiricist thinkers he not only influenced British philosphers from Hume to Russell and the logical positivists in the twentieth-century, he also set the scene for the continental idealism of Hegel and even the philosophy of Marx. This edition of Berkeley's two key works has an introduction which examines and in part defends his arguments for idealism, as well as offering a detailed analytical contents list, extensive philosophical notes, and an index.