Berkeley's idealism started a revolution in philosophy. As one of the great empiricist thinkers he not only influenced British philosophers 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. There has never been such a radical critique of common sense and perception as that given in Berkeley's Principles of Human Knowledge (1710). His views were met with disfavour, and his response to his critics was the Three Dialogues between Hylas and Philonous. 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.