Berkeley, George (1685–1753)

George Berkeley was one of the great thinkers of the post-Descartes period of European modern philosophy. An important critic of the philosophers René Descartes and John Locke, he developed and defended a form of philosophical idealism, the view that only minds and their ideas are real. He had significant influence on David Hume and Immanuel Kant, and his work is still taught regularly in contemporary modern philosophy courses.

George Berkeley was born near Kilkenny, Ireland. At age 15, after some years studying at Kilkenny College, he entered Trinity College in Dublin. He became a fellow of Trinity College in 1707 and soon after was ordained in the Anglican Church. At Trinity College, Berkeley's philosophical idealism began to emerge in response to his study of figures like Descartes, Locke, Nicolas Malebranche, Isaac Newton, and Thomas Hobbes.

Berkeley's most important works were published while he was in his 20s: An Essay Towards a New Theory of Vision (1709); Treatise Concerning the Principles of Human Knowledge (1710); and Three Dialogues Between Hylas and Philonous (1713).

In his 30s he spent a 4-year tour in Europe as tutor to a young man. His resumption of his position at Trinity led to his appointment as Dean of Derry in 1724. At about this time he began to prepare to launch a college in Bermuda. In 1728, with his new bride, Anne Forster, he left for America (Newport, Rhode Island) to wait for British Parliament funds for this project. The money never materialized, and he was forced to return to Britain in 1731. In 1734 he was appointed Bishop of Cloyne, and thus he returned to Ireland. Here he wrote his last philosophical work, Siris (1744), which became a bestseller, on the medicinal and religious power of tar-water (a liquid prepared by letting pine tar stand in water). Berkeley died in 1753, shortly after moving to Oxford to supervise the education of one of his three surviving sons, George.

Berkeley's two great works of philosophy (the Treatise and Dialogues) are primarily a defense of idealism. A key part of this defense rests on a systematic attack on “materialism,” namely, the view that material things exist. By material things Berkeley meant things that can exist independently of minds. Such independent existence had been held prominently by Descartes and Locke (who were dualists,). Berkeley, argued that no mind-independent physical objects are possible. On the contrary, for Berkeley, to exist is to be perceived or to perceive—esse est percipi (out percipere)

Consistent with his idealism, Berkeley did not view time as existing independently of its being perceived by minds. Along with Gottfried Wilhelm von Leibniz, he denied Newton's idea of a fixed frame of reference for the motion of objects—namely, absolute time (and absolute space). For Berkeley, because to be is to be perceived, and absolute time itself cannot be perceived, absolute time is not real. Time for Berkeley is merely “the succession of ideas.” To remove the train of ideas that minds experience is to remove any notion of time.