Journeys of Janus: George Berkeley


Esse estpercipi. (To exist is to be perceived.)

—George Berkeley 1

In the 9th century, Eriugena had propounded a metaphysic that was bold and complex. In the 18th century, George Berkeley propounded a metaphysic equally bold, but bold in simplicity rather than complexity. These two systems, so different in detail and texture, concur in vision and outlook: A beneficent God creates human beings as spirits in a hospitable universe; and, through the hospitality of the universe, God and humankind remain intimately related.

Berkeley claims that just two kinds of things exist: Minds and ideas. Of these, only minds or spirits constitute substance. Minds have ideas. Ideas exist because of minds. To exist is to perceive, or be perceived, or be perceivable. An idealism, in the metaphysical sense, is a theory that bases reality on mind. George Berkeley is Western philosophy’s most famous idealist. 

On the surface, idealism seems preposterous. Just minds and ideas exist? Not material objects? What of chairs, desks, and books? What of mountains, streams, and stones? The English essayist Dr. Sam Johnson, when asked about Berkeley’s idealism, responded by kicking a rock and saying, “I refute it thus!” Dr. Johnson’s reaction typifies the attitude of people before they have studied Berkeley. The person who has read Berkeley knows that, whatever mistakes Berkeley may have made, kicking a stone does not refute him. Berkeley accounts for all items our world of experience, stones no less than anything else. Indeed, Berkeley claims that not his own metaphysic but its alternative fails to account for the ordinary things in our world. What does he mean?

George Berkeley was born near Kilkenny, Ireland, in 1685. By the age of nineteen he had graduated from Trinity College, Dublin. At 22, Trinity elected him to fellowship. Between then and his twenty-eighth birthday—between, that is, 1707 and 1713—he did most of his philosophical writing. Thus, this precocious philosopher was born and matured intellectually during another birth, the extraordinary birth of modern experimental science.

In those years, intellectuals were optimistic. Many believed that soon, within decades, all secrets to the universe would be solved. Berkeley himself was impressed by the growth of scientific knowledge. He appreciated the astronomy of Galilei Galileo, the physics of Isaac Newton, the chemistry of Robert Boyle. Though he applauded the results of their investigations, he deplored the theory whereby their investigations were usually explained and justified. He worried not at all about the burgeoning science; rather, he worried about the prevailing philosophy of science.

That philosophy of science was mechanistic. Advocates of mechanism,2 such as John Locke (1632-1704), claimed that reality consists of indestructible atoms moving in an infinite void. The atoms have various shapes, sizes, masses, and motions. Events at this microscopic, atomic level explain all events at the ordinary, macroscopic level; and all events at the atomic level consist of impacts of one sort or another. Scientific explanation is mechanical purely. Any non-mechanical explanation would need to be theological: God does decree occasional exceptions to the macroscopic consequences of the microscopic impacts.

Many mechanists believed that the atoms comprised a substrate or metaphysical foundation for the world that we experience. The substrate, being universal, applies to experience itself. Whether visual, auditory, tactual, olfactory, or gustatory, our experience results from the atoms’ impacts on sensory organs, the experience varying according to variations in the atoms’ shapes, sizes, masses, and motions.

Mechanism may seem harmless enough. In fact, it resembles the common view of reality held by many people today. John Locke, however, expounded a further claim about perception: All that we know directly is our own ideas. Locke’s claim resounds through Western thought to the present day. If some collection of atoms, call it CA1, affects some mind, call her Mindy, and, through that impact only, creates in Mindy an experience, call it EXP1, EXP1 is distinct from CA1. Mindy knows everything about EXP1 and nothing about CA1. The substrate, which causes all perceptions, escapes all perceptions. The cause of experience is itself beyond experience. 

Berkeley identifies an insidious implication of Lockean mechanism: We can know nothing about our world. This implication mocks commonsense. We all believe—except for a tiny group of skeptics—that we can directly know certain things about the world of our experience. Berkeley agrees emphatically. He does not maintain that we know everything about the world, or even that we know much. Rather, he maintains that we directly know something. Any philosophy of science that entails that we directly know nothing makes a big mistake. Indeed, for a philosophy of science to imply that knowledge of objective reality cannot be achieved is contradictory. What irony it is that the enthusiastic proponents of scientific possibility explain their science with a philosophy of ultimate cognitive impossibility.

Berkeley moves deftly. He eliminates the atomic substrate. In our example, there is no theoretical difficulty in positing that Mindy has direct knowledge if reality consists only of Mindy herself and her experience EXP1. She has the kind of acquaintance with the world that we believed in all along, direct acquaintance, sensory acquaintance. As we would say in the 21st century, people have sensory experiences. Or, as Berkeley would say, people have “ideas.” Having ideas just is to understand the objective world. 

This position seems strange at first, less so upon analysis. After all, what is an apple but its collected sensory qualities? Remove its redness, remove its tartness or sweetness, remove its crunchiness, remove any aroma, remove the roundness, and what’s left? Nothing. It is “material” only in the sense that it exists. People use the word ‘material’ just to mean that a particular collection of sensory qualities appears to us vividly and dependably. To say that the collection is material in the mechanists’ conception of matter, as the apparent result of a cause that remains forever unapparent, is false or, worse, incoherent.

Berkeley’s world is at once enormously varied, rationally organized, and stunningly, elegantly simple. Minds have ideas, a manifold of ideas. Contrary to Dr. Johnson, no stone is left unaccounted for.

If, however, minds have ideas, if, that is, the existence of ideas depends solely on their being perceived, the objective, continuous existence of the world of our experience seems jeopardized. Suppose a woman is fly-fishing. Having no luck, she removes the brightly colored fly that she has been casting. She ties on a brown and grey fly, wondering whether this darker pattern will work better. Does the bright fly, now stored in a small tackle box, out of sight and mind, no longer exist? A critic reasons:

  1. If existence depends on perception, a woman’s ceasing to perceive a fly annihilates the fly.

  2. A woman’s ceasing to perceive a fly does not annihilate a fly.

  3. Therefore, existence does not depend on perception.

Berkeley believes 1 is false. He reasons:

  1. If a woman’s ceasing to perceive a fly does not annihilate the fly, another spirit must continue to perceive the fly.

  2. A woman’s ceasing to perceive a fly does not annihilate the fly.

  3. Therefore, another spirit continues to perceive the fly.

The woman, however, may fish alone. No one sees her tackle box; no one sees the fly. Yet we know that the little lure continues to exist. Our commonsense tells us so. Only the Author of Nature, the Spirit that creates all spirits and ideas, can provide the continuity necessary to accommodate our ordinary beliefs about reality.

[S]ensible things cannot exist otherwise than in a mind or spirit. Whence I conclude, not that they have no real existence, but that seeing they depend not on my thought, and have an existence distinct from being perceived by me, there must be some other mind wherein they exist. As sure therefore as the sensible world really exists, so sure is there an infinite omnipresent spirit who contains and supports it3

The 21st century reader will pause here. The credibility of Berkeley’s metaphysic has survived one obstacle only to encounter a second. The first is the disavowal of matter. Odd as the disavowal seems, perhaps we can accept it. After all, what is an apple but its sensory qualities? We’re with Berkeley so far, cautiously.

To reconnect the mind to reality, however, Berkeley removes from reality that very concept, matter, which we had thought connected reality to objectivity. To solve this new problem, the reconnection of reality to objectivity and continuity, Berkeley invokes God. God is the Prime Thinker, the Ultimate Subject of ideas, thereby the Sustainer of all objectivity. Berkeley’s move may seem artificial, ad hoc. Is it not just a deus ex machina, contrived to save his story? Anthony Kenny summarizes the situation.

Even if we grant that the sensible world consists only of ideas, there seems to be a flaw in this proof of God’s existence. One cannot, without fallacy, pass from the premise ‘There is no finite mind in which everything exists’ to the conclusion ‘therefore there is an infinite mind in which everything exists’. (Compare ‘There is no nation-state of which everyone is a citizen; therefore there is an international state of which everyone is a citizen.’)4

The suggested criticism of Berkeley, which Kenny leaves undeveloped, does not seem to work because the analogy on which it is based fails. The presumed analogy is between the relationship between humanness and citizenship, on the one hand, and, on the other hand, the relationship between the existence of sensible things and their status as objects of perception. True, citizenship does not inhere in humanness, thus, that a human being lacks citizenship in a nation-state does not entail that she has citizenship in some other kind of state.

But the situation differs regarding the relationship between a sensible thing and its status as an object of perception. As soon as Kenny grants that the sensible world consists only of ideas, that a sensible thing lacks the status of being perceived by any finite minds does entail that it has the status of being perceived by one or more infinite minds. Thus, the criticism fails because the analogy on which it is based fails. The result, nevertheless, would not be to Berkeley’s liking, for we seem to have shown the cogency of the following argument.

  1. Some things exist in no finite mind.

  2. Therefore, there are one or more infinite minds in which everything exists. 

From the perspective of a monotheist, Berkeley seems to support the existence of too many Gods. Berkeley would almost certainly resist 8.5 Whether he can resist it consistently within the resources of his philosophy is a question that we leave unexplored.

One final aspect of Berkeley’s thought deserves attention. Berkeley believes that God speaks to humankind through nature. Jonathon Dancy emphasizes this component; indeed, he develops it more fully than does Berkeley himself.6 To reflect Dancy’s contribution, in the exposition that follows we use the broad expression, ‘Berkeleyan position’. At first blush, the Berkeleyan position seems unsurprising—if anything, clichéd, since theists often wax romantic about the beauties of nature. For example, “I know there is a God. I see Him every time the sun sets.” Or, “I know there is a God. He speaks to me every time the sun sets.” Almost always, however, theists intend such utterances figuratively. 

Other times theists do assert that God communicates through nature literally, but their assertion concerns not nature’s concordance with physical law but nature’s departure from physical law. They say that a miracle has occurred.7 Berkeley, however, asserts neither that God speaks through nature figuratively nor that God speaks through nature primarily in miracles. (Berkeley does believe that God speaks through nature in miracles, but such communication is secondary.) Rather, Berkeley claims that ordinary, not miraculous, natural events constitute literal, not figurative, communication from God.

To illustrate the Berkeleyan position, we amend the example of the setting sun. A gardener says, “The sun is setting. The temperature is already near freezing. I had better go out and cover my succulents, which are vulnerable to frost.” The gardener, experienced as he is, knows how to read that part of nature that pertains to gardening. Indeed, we all can read nature to a degree. Nature is a text. Each person reads accurately the parts of the text with which she has become acquainted through her particular occupation and interests. Scientists excel in reading special parts. ‘Read’ is literal. 21st century quotation marks express the point: We should not say that the biologist “reads” nature; rather, we should say that the biologist reads nature. 

‘Reads’, ‘text’, and ‘language’ are literal because, in the Berkeleyan view, nature shares a fundamental property with other language: Its meanings are arbitrary and conventional. For example, English-speaking residents of the United States, mean by ‘car’ either ‘automobile’ or ‘railroad vehicle’ because, and only because, people in the United States so use the word; by contrast, English-speaking residents of the British Isles mean by ‘car’ either ‘automobile’ or ‘city tramway vehicle’ but not ‘railroad vehicle’ because, and only because, people in the British Isles so use the word. Meanings do not inhere in words; they adhere to words. They adhere as usage attaches them to words. They are arbitrary and conventional.

Berkeley believes that, much as meanings do not inhere in words, meanings do not inhere in nature. To nature God attaches meanings. God determines the meanings. God could determine them otherwise. Meanings are thus conventional, for they depend entirely on God’s will. God’s establishment of meanings, which we can apprehend, reflects God’s incomparable beneficence: Because we can learn to read nature, we can avoid the wide range of potential harms and attain the wide range of potential goods.

Dancy emphasizes that, for Berkeley, when we read the language of nature, we do practice science, but we do not identify causal relations. Rather, we identify regularities.8 Berkeley believes that only minds, not ideas, are active. Since ideas in collection constitute sensible objects, and since ideas are inactive, causation between objects is a myth. On this line of thinking, scientists, when conceiving their work properly, search for regularities between events, but not causal regularities.

Dancy designates these Berkeleyan regularities, “semantic necessities.”9 We all pursue semantic necessities, whether we are scientists or not. Our gardener reasons, “The sun is setting. The temperature is already near freezing. I had better go out and cover my succulents, which are vulnerable to frost.” The three premises—about the sun, the temperature, and the nature of desert plants—give the gardener a basis for action. He lives neither in a random world, nor in a world of causal necessity; but, rather, in a world of semantic necessity.

Berkeley deserves more sustained attention than he has received. On first encounter, his idealism appears implausible. This appearance fades with examination. The appearance may say less about the inadequacies of his philosophy than it does about the preconceptions of our own age. Berkeley had worried that it would come to this, that the de-spiritualizing tendencies of mechanism would lead to atheism. God would come to be seen as metaphysically superfluous, epistemically mythical, and personally irrelevant. Given the prevalence today of atheism and moral relativism among Western intellectuals, Berkeley’s worries now seem foresighted.

The 9th century Eriugena, and the 17th and 18th century Toland and Berkeley, exemplify, in their own ways, the related themes of divine immanence and optimism about human beings. Berkeley’s linguistic construction of the natural world epitomizes his emphasis on the divine immanence, the hospitality of the universe to human beings, the capacity of human beings to appropriate and appreciate that hospitality. Dancy writes,

If the experienced world constitutes a series of language-like utterances of God’s, which we can come to understand in the way in which we understand human utterances and language, we have found yet another sense in which Berkeley’s God is far closer to us in our ordinary experience of the world than as conceived in ordinary religious belief.10

Although Berkeley abhors mechanistic philosophy of science, he respects the science itself. Even in a less inventive philosopher, a respect for science should follow from an honest doctrine of immanence: Created in the divine image, nature is good; thus the knowledge of nature should also be good. Berkeley goes further: The divine Mind composes nature; thus scientific knowledge constitutes knowledge of God’s own discourse to humankind. The pursuit of science, then, is not merely prudentially, but also religiously, commendable. As Dancy says, “For Berkeley, the attempt to understand better the utterances of God has an obvious moral worth, since it is just the attempt to get closer to God.”11


  1. (Back to text)

  2. (Back to text) Mechanism was also called “corpuscularianism.”

  3. (Back to text) Berkeley, Principles of Human Knowledge and Three Dialogues edited by Howard Robinson (Oxford, 1996), Second Dialoge, 152.

  4. (Back to text) Anthony Kenny, A Brief History of Western Philosophy(Blackwell, 1998), 234.

  5. (Back to text) In 1709, Berkeley was ordained in the Anglican Church of Ireland. He was appointed Dean of Derry in 1724, and Bishop of Cloyne in 1734. The Anglican Communion includes the Episcopal Church of the United States. Anglicans stand midway between Roman Catholics and Protestants, sharing with the former a belief in the Apostolic succession of bishops, with the latter claim to be heirs of the Reformation.

  6. (Back to text) Jonathan Dancy, Berkeley: An Introduction (Blackwell, 1987), 109-128.

  7. (Back to text) Granted, people often use ‘miracle’ figuratively, as in, “It was a miracle that I got an A on that test.” Other uses are ambiguous, as in, “It was a miracle that the baby fell from the third story window and survived.”

  8. (Back to text) Ibid., 117.

  9. (Back to text) Ibid.

  10. (Back to text) Dancy, 110.

  11. (Back to text) Ibid., 118-9.