George Berkeley

Key ideas

1. Immaterialism. Berkeley denies that there is any mind-independent material substance. What exists is minds, which perceive and act, and ideas, which are perceived. He presents this as a defence of common sense, since he accepts that the things we see and touch really exist.
2. To be is to be perceived. Ordinary objects are collections of ideas, and ideas exist only in a mind. Of sensible things, then, esse is percipi: their being is to be perceived. A table or a tree is real, but it exists in the mind of a perceiver.
3. The likeness principle. An idea can be like nothing but an idea, so the claim that our ideas resemble mind-independent bodies cannot be supported. Berkeley argues that shape and motion, which Locke counted as primary qualities, are as relative to the perceiver as colour and taste.
4. Against abstract ideas. We cannot form an idea of a man, or of a triangle, that is not of some particular one. A general word works by standing for any of many particular ideas, and Berkeley blames the doctrine of abstraction for many philosophical confusions.
5. God and the order of nature. Ideas of sense do not depend on our wills and come in regular patterns, which are the laws of nature. Berkeley argues that they are produced by an infinite spirit, God, in whose mind things also subsist when no finite mind perceives them.
6. Vision and Molyneux's problem. Distance is not seen directly, and the ideas of sight and touch have nothing in common. Someone born blind who gained sight would therefore have to learn which visual idea goes with which tangible one.
7. Science and mathematics. In De Motu Berkeley argued against Newton’s absolute space and took an instrumentalist view of mechanics, treating its principles as tools for calculation. In The Analyst he attacked the logical foundations of the calculus.

George Berkeley (1685–1753; pronounced BARK-lee) was an Anglo-Irish philosopher and Anglican bishop who argued that there is no material substance. The world consists of minds and the ideas they perceive, a doctrine called immaterialism or subjective idealism, and ordinary things are real because they are perceived: esse est percipi, to be is to be perceived. He published his main works before he was thirty, and Hume and Kant both took them up.

He was born near Kilkenny, entered Trinity College Dublin at fifteen and became a fellow in 1707. An Essay Towards a New Theory of Vision (1709), the Principles of Human Knowledge (1710) and the Three Dialogues between Hylas and Philonous (1713) followed. He sailed for America in 1728 to found a college in Bermuda; the promised funds never came, and he returned to Britain in 1731. In Rhode Island he bought enslaved people to work his farm, and Trinity College Dublin has since taken his name off its main library. He became Bishop of Cloyne in 1734 and died in Oxford on 14 January 1753.

What does “to be is to be perceived” mean?

Berkeley begins with a table. “The table I write on I say exists, that is, I see and feel it,” he writes in the Principles (§3), and out of his study it would still “exist” in the sense that he might perceive it, “or that some other spirit actually does perceive it.” Everything we know of such an object reaches us as ideas of sight, touch and the rest, and an apple is a collection of ideas that go together. Ideas exist only in a mind, so of sensible things esse is percipi, Berkeley’s own anglicised form of the Latin tag.

Does Berkeley deny that the world exists?

He says plainly that he does not. “I do not argue against the existence of any one thing that we can apprehend either by sense or reflexion,” he writes in §35; what he denies is “that which philosophers call matter or corporeal substance”, a mind-independent something behind the ideas. Real things differ from dreams, he argues, in being orderly and independent of our wills.

His motives were partly religious. He thought that materialism leads to scepticism, since we can never check ideas against bodies we cannot perceive, and to atheism, since a material world could run without God.

Why did he think matter was a mistake?

The core is the likeness principle: “an idea can be like nothing but an idea; a colour or figure can be like nothing but another colour or figure.” Locke held that ideas of primary qualities such as shape resemble qualities in bodies, while colour and taste exist only in the perceiver. Berkeley replies that the primary and secondary qualities stand or fall together. In the First Dialogue Philonous argues from relativity: what feels hot to one hand feels cold to another, and Hylas concedes that “the least pain cannot exist unperceived.”

Behind this lies his attack on abstraction. The idea of a man, he says, must be the idea of some particular man, and “a word becomes general by being made the sign, not of an abstract general idea, but of several particular ideas.” That is his contribution to the problem of universals.

What is the master argument?

Hylas objects: “What more easy than to conceive a tree or house existing by itself, independent of, and unperceived by, any mind whatsoever?” Philonous replies that the tree is then conceived by Hylas, and “what is conceived is surely in the mind.” Berkeley was “content to put the whole upon this issue.” Most commentators think the argument fails, because it runs together conceiving a tree and the tree conceived, though the Stanford Encyclopedia discusses more charitable readings.

What happens when nobody is looking?

Berkeley’s answer is God. Things not perceived by any created mind “must either have no existence at all, or else subsist in the mind of some eternal Spirit.” The order of sense ideas is not of our making, so he infers an infinite spirit as its cause. Interpreters disagree about how far he relies on God’s perceiving and how far on what would be perceived under the right conditions.

Vision, motion and the calculus

In the Essay Berkeley argues that distance is not seen directly and that sight and touch share no ideas, so his answer to Molyneux’s problem is that a newly sighted person could not tell a cube from a sphere by looking. In De Motu he criticised Newton’s absolute space, and in The Analyst (1734) he asked of the vanishing increments of the calculus: “May we not call them the Ghosts of departed Quantities?”

How was he received?

Hume wrote in a note to the first Enquiry that Berkeley’s arguments “admit of no answer and produce no conviction.” Samuel Johnson, according to Boswell, struck a large stone with his foot and said “I refute it thus”, which misses the target, since Berkeley agreed that the stone is real. The University of California, Berkeley, is named after him.

How should you start reading Berkeley?

Read §§1–7 of the Principles, then the First Dialogue, which is easier to read. The UGC NET syllabus lists Berkeley’s immaterialism, critique of abstract ideas, esse est percipi and the problem of solipsism; see the UGC NET guide and the UPSC guide.