George Berkeley (1685–1753), an Irish philosopher and Anglican bishop, was educated at Trinity College, Dublin, where he subsequently taught. There he wrote An Essay Towards a New Theory of Vision (1709), A Treatise Concerning the Principles of Human Knowledge(1710), and Three Dialogues Between Hylas and Philonous (1713) from which the present selections are taken. At this time he became an Anglican priest and moved to London. In the 1720s he helped plan a college in Bermuda for sons of settlers and native Americans. In 1728 he married Anne Forster and sailed to Newport, Rhode Island, where he waited for promised government support for the college. It never came, and the college was never established. In 1731 he returned to London, where he wrote The Theory of Vision (1733). From 1734 to 1752 he served as Bishop of Cloyne, Ireland. A deeply committed Christian, he sought to reconcile science with his faith by proving that matter does not exist, and that the laws of physics, being God's laws, govern a universe made up of ideas.
Berkeley's fame rests on his development of a type of Idealism, better called “ideaism” or “Immaterialism,” and for his incisive critique of Locke's Representationalism. It should be noted that Berkeley's Idealism is different from traditional idealism (e.g., Plato's), in that it is not rationalistic. It does not adhere to independently existing ideas, but rather it assumes an empirical foundation. It agrees with Locke that all ideas originate in sense experience, and proceeds to show that all we ever experience is ideas, our sensations or sense perceptions. The only reality there is to be known is perceivers and perceptions.
Concerning Locke's theory of knowledge, Berkeley argued, first, that the primary/ secondary qualities distinction was exceedingly weak. The primary qualities are no more “in” the objects of perception than the secondary ones. Second, he argued that there were logical problems in the theory that our perceptions resembled physical objects (“an idea can be like nothing but an idea”). Third, he undermined the whole notion of substance which Locke needed to maintain his theory. What is the difference, Berkeley rhetorically asked, between a “something I know not what” (Locke's notion of substance) and nothing at all? Ultimately, Locke's Representationalism leads back to skepticism. Finally, Locke's theory was an explanatory failure. Locke asserted that ideas in the Mind were caused by mechanical actions upon our sense organs and brains. But Berkeley pointed out that this fails to explain mental events both in detail and principle: in detail because it was impossible to explain why a certain physical event should produce certain but quite different (in character) mental states (e.g., light waves producing the color red); in principle because the whole notion of dualistic interactionism was incoherent, misusing the notion of “cause.” A cause makes something happen, but for this you need a notion of a WILL, agency—all causation is agent causation, but events in Nature do not make other events happen. One sees only two events in temporal succession—with regularity. But this only signals the reality of a cause; it is not the cause, for it is not an agent and exerts no will.