George Berkeley: Immaterialism & Philosophy

Biography

George Berkeley was born on March 12, 1685, near Kilkenny, Ireland, of English ancestry. He was educated at Kilkenny College and at Trinity College Dublin, where he was elected a fellow in 1707. Berkeley's philosophical career began early and brilliantly: he published his Essay Towards a New Theory of Vision in 1709 and his Treatise Concerning the Principles of Human Knowledge in 1710, when he was only twenty-five. His third major work, Three Dialogues between Hylas and Philonous, appeared in 1713.

Berkeley was not only a philosopher but also a clergyman and missionary. He was ordained in the Church of Ireland and dreamed of founding a college in Bermuda for the education of colonists and Native Americans; although the project collapsed, his journey to America (1728–1731) left its mark on the cultural life of the colonies, and the city of Berkeley, California, is named in his honor. He served as Bishop of Cloyne from 1734 until his death on January 14, 1753, in Oxford. His later years were devoted to theological and medical writing, including the remarkable Siris (1744), which argued for the health benefits of tar water.

Historical Background

Berkeley's philosophy was forged in the crucible of early modern philosophy. The dominant picture at the turn of the eighteenth century was that of John Locke: the mind is a blank slate on which experience writes, and the senses provide us with ideas that represent an external world of material objects. Locke distinguished between primary qualities (extension, solidity, motion — qualities that exist in the objects themselves) and secondary qualities (color, sound, taste — qualities that exist only in the mind).

Berkeley saw a fatal instability in this Lockean picture. If all we ever perceive are ideas, then we have no direct access to material substance; the material world becomes a theoretical posit that can never be observed. Moreover, the distinction between primary and secondary qualities cannot be maintained: extension and motion are as relative to the perceiver as color and taste. A foot-long object appears many feet long to a small creature; the shape of an object changes with perspective. If the secondary qualities are mind-dependent, Berkeley argued, so are the primary ones. The conclusion he drew was radical: there is no material substance at all.

Core Ideas

Immaterialism and Esse Est Percipi

Berkeley's positive thesis is that reality consists of minds (spirits) and their ideas. The essence of an idea is to be perceived: "esse est percipi" — to be is to be perceived. A table, an apple, or a mountain is nothing over and above the collection of ideas (of color, shape, texture, taste) that perceivers have of it. There is no material substratum that underlies these ideas; the things of the world just are the ideas, and their existence consists in their being perceived.

This is not skepticism about the external world but a reinterpretation of it. Berkeley insisted that his philosophy was the great defender of common sense: we continue to perceive the same stable world, but we no longer need to believe in a mysterious material substance that no one has ever perceived. What we perceive, we perceive directly, and the world of perception is the real world.

The Role of God

If to be is to be perceived, what happens to objects when no human perceives them? Berkeley's answer is that God, an infinite spirit, continuously perceives everything. The "real" existence of the things of the world consists in their being perceived by God; human perceivers come to share in that perception. This theological move secures the continued existence of the world and grounds the regularity of nature: the "laws of nature" are the regular patterns according to which God presents ideas to finite minds. Far from being an embarrassment to his system, the appeal to God is its keystone.

The Critique of Abstract Ideas

Berkeley also attacked the doctrine of abstract ideas, which he attributed to Locke. According to the doctrine, the mind can form abstract general ideas — the idea of triangle in general, which is neither scalene, isosceles, nor equilateral. Berkeley argued that such ideas are impossible: we can form images of particular triangles, but not of triangle as such. General terms, he held, do not name abstract ideas but stand for particular ideas taken as representatives of a class. This critique influenced the later empiricism of David Hume and the linguistic turn in philosophy.

The Theory of Vision

In his New Theory of Vision, Berkeley argued that visual perception does not directly reveal distance, magnitude, or situation. The eye receives only a two-dimensional array of colored patches; our perception of a three-dimensional world is built up through the learned association of visual ideas with tactile ideas. This theory, which treats vision as a kind of language that we learn to read, was remarkably prescient and is regarded as a founding contribution to the psychology of perception.

Major Works

A Treatise Concerning the Principles of Human Knowledge (1710) is Berkeley's systematic statement of immaterialism, comprising an introduction on abstract ideas and a first part on the principles of human knowledge. Three Dialogues between Hylas and Philonous (1713) restates the doctrine in dialogue form and answers objections, including the charge that immaterialism abolishes the distinction between reality and illusion. An Essay Towards a New Theory of Vision (1709) presents his account of visual perception. Siris (1744) is a late work on tar water and natural philosophy that also reflects on the unity of the world.

Philosophical Influence

Berkeley's immaterialism is the purest expression of idealism in the British empiricist tradition, and it set the agenda for every later form of idealism from Kant to the phenomenologists. His critique of the distinction between primary and secondary qualities remains a classic argument, and his attack on abstract ideas helped shape the development of empiricist semantics. His account of perception influenced the psychology of vision, and his insistence that the objects of perception are directly given influenced twentieth-century phenomenology and the debate about direct realism.

In the philosophy of mind, Berkeley is a decisive figure in the history of the question of consciousness and the external world. His argument that the world of perception is a world of experience foreshadows modern questions about the relation between mind and reality and about whether we can know a world beyond experience. Critics, beginning with Hume and continuing to the present, have found the appeal to God unconvincing, but the elegance and rigor of Berkeley's system have never ceased to fascinate. As Thomas Nagel observed, the idealist impulse Berkeley represents remains live in contemporary debates about the nature of consciousness.

Related Concepts

Berkeley's immaterialism is a landmark in the history of idealism and empiricism. His arguments bear directly on the mind-body problem and on the question of what is consciousness. His critique of material substance prefigures modern questions about whether physical reality is fully mind-independent, and his theory of perception connects to the study of direct experience and self-knowledge. For understanding how the question of consciousness first arose in its modern form, Berkeley's Principles remains indispensable.