  George Berkeley, Bishop of Cloyne, was one of the great philosophers of the early modern period. He was a brilliant critic of his predecessors, particularly Descartes, Malebranche, and Locke. He was a talented metaphysician famous for defending idealism, that is, the view that reality consists exclusively of minds and their ideas. Berkeley’s system, while it strikes many as counter-intuitive, is strong and flexible enough to counter most objections. His most-studied works, the Treatise Concerning the Principles of Human Knowledge (Principles, for short) and Three Dialogues between Hylas and Philonous (Dialogues), are beautifully written and dense with the sort of arguments that delight contemporary philosophers. He was also a wide-ranging thinker with interests in religion (which were fundamental to his philosophical motivations), the psychology of vision, mathematics, physics, morals, economics, and medicine.  Although many of Berkeley’s first readers greeted him with incomprehension, he influenced both Hume and Kant, and is much read (if little followed) in our own day.