George Berkeley, the Irish philosopher of English ancestry, and Anglican bishop of Cloyne, was born at Kilkenny, Ireland. He entered Trinity College, Dublin in 1700 and became a fellow in 1707. In 1709 he published his first important book, An Essay towards a New Theory of Vision. This was well received, and a second edition appeared in the same year. The following year A Treatise concerning the Principles of Human Knowledge, Part 1, was published. This is the work in which Berkeley first published his immaterialist philosophy, and although it made him known to some of the foremost writers of the day, its conclusions were not taken very seriously by them. In 1713 Berkeley went to London and there published the Three Dialogues between Hylas and Philonous, a more popular statement of the doctrines of the Principles. While in London, Berkeley became acquainted with Joseph Addison, Jonathan Swift, Alexander...