One Strange Idea: That Nothing Is "Out There"
Imagine you’re sitting in your room. There’s a chair across from you, a window with sunlight coming through, and a book in your hands. Now close your eyes.
Does the room still exist?
Most people would say: of course it does. The chair is still there, the sunlight is still streaming in. You just can’t see it right now. The room is “out there,” minding its own business, whether you’re looking at it or not.
Now imagine you leave your house, walk three blocks to school, and sit down in your first class. Does your room still exist? The chair, the window, the book—are they still back there, waiting for you to return?
Again, most people would say yes. Of course they are. Things don’t just vanish when nobody’s looking at them.
But a philosopher named George Berkeley (1685–1753) thought this commonsense view was wrong. Not just slightly wrong, but completely, radically, head-spinningly wrong. He thought the whole idea of a world that exists “out there,” independent of minds, was a mistake. He thought—and this is the strange idea—that to be is to be perceived.
The Shortest Argument in Philosophy
Berkeley was a young man when he wrote his most famous books—still in his twenties. He was a bishop in the Church of Ireland, deeply religious, and he thought the science and philosophy of his day were leading people toward atheism and doubt. He wanted to show that the only things that exist are minds and the ideas they perceive. Nothing else. No “matter.” No “physical substance” lurking behind our experience.
He starts with a very short argument:
- We perceive ordinary objects like houses, mountains, and trees.
- We perceive only ideas (the things in our minds—colors, shapes, sounds, smells).
- Therefore, ordinary objects are ideas.
If you’re thinking “Wait, that’s too fast,” you’re right. The trick is in the second step. Berkeley thought that Descartes and Locke—the most famous philosophers before him—actually agreed with it. They thought we perceive only our own ideas, and that those ideas are representations of a real world outside us. So when you see a tree, you’re seeing a mental picture of the tree, not the tree itself.
Berkeley just took their logic one step further. If all we ever perceive are ideas, he said, what reason do we have to believe in anything else? What does it even mean to say there’s a real tree “out there” that our ideas represent? We’ve never seen it. We can’t compare our ideas to it. It’s a ghost—something we made up and then can’t find.
The Problem with “Out There”
The philosophers Berkeley was arguing against had a picture like this: There’s a world of physical stuff (tables, trees, rocks) made of matter. This stuff has properties like size, shape, and motion. When it bumps into our sense organs, it somehow produces ideas in our minds—colors, sounds, smells, feelings of warmth. These ideas are in our heads, but they represent the real stuff out there.
Berkeley thought this picture was broken in three ways.
First, the “likeness problem.” If we want to say that our idea of a tree is like the real tree, we need to compare them. But we can only compare things we perceive. We can compare two ideas. We can compare an idea to a memory. But we can never compare an idea to something we don’t perceive—something outside our mind entirely. So the claim that ideas resemble external objects is empty. It’s like saying a drawing of a dragon resembles a real dragon, when you’ve never seen a real dragon and can’t check.
Second, the “causation problem.” How does matter cause ideas? Descartes himself admitted he couldn’t explain it. How does a lump of physical stuff—which has no thoughts, no feelings, no consciousness—produce a thought in a mind? It’s like saying a rock can write a poem. Nobody could really explain it. So why believe in matter if it doesn’t even do the job it’s supposed to do?
Third, the “relativity problem.” Things look different from different angles and to different creatures. The same water feels hot to one hand and cold to another (if one hand has been in ice water and the other in warm water). The same object looks small from far away and big up close. To a tiny insect, a leaf must look enormous. Which one is the real size, the real temperature? If objects really have definite properties “out there,” we can’t decide which ones they are. The simplest explanation is that all these qualities depend on the perceiver—which means they’re in the mind, not in the world.
So, What Is an Apple?
If you accept Berkeley’s argument, you have to say that a thing like an apple is just a collection of ideas—the red color you see, the smooth feel in your hand, the sweet taste, the smell. When these ideas regularly come together, you give them a name: “apple.” There’s no hidden apple-stuff underneath them. The apple is the bundle of perceptions.
This sounds weird, but notice something: Berkeley isn’t saying apples don’t exist. He’s saying they exist exactly as we experience them, not as something hidden behind our experience. He thought this was actually more commonsensical than the alternative. After all, when you eat an apple, you experience its taste and texture and color. You don’t experience some invisible apple-substance that causes taste and texture and color. That invisible substance is a philosophical invention.
But here’s the natural objection: If everything is just ideas in minds, then what’s the difference between a real apple and an imaginary apple? Between a real fire (hot!) and a daydream about a fire? What about when you leave the room—does the apple just vanish?
Berkeley had answers.
Real vs. imaginary: Real things are ideas that God puts in our minds in a regular, orderly, predictable way. They’re vivid, steady, and they follow rules (what we call “laws of nature”). When you touch a real fire, you get burned—every time, predictably. Imaginary fires don’t burn. Real apples are real because God produces apple-ideas in any perceiver who looks in the right place at the right time.
Vanishing apples: This is the tough one. If to be is to be perceived, then when nobody perceives the apple, doesn’t it stop existing? Berkeley said something clever: God always perceives everything. So the apple is always being perceived by God, even when no human is looking. That’s why the apple in your room doesn’t vanish when you close your eyes—God is still perceiving it. (This is the source of the famous limerick: “There was a young man who said, God / must think it exceedingly odd / if he finds that the tree / continues to be / when no one’s about in the Quad.”)
God, in this system, is the ultimate perceiver and the cause of all our sense experiences. He’s the one who makes the world regular and predictable, so that when you look for your apple, it’s there.
The Problem Berkeley Creates
You might notice that Berkeley’s picture has a weird consequence. If you and your friend are looking at the same tree, you each have your own tree-idea in your own mind. They’re not the same idea—you can’t share a mental image. So do you perceive the same tree?
Berkeley says yes, but in a loose sense. It’s like two people looking at the same movie. They’re each having their own experience, but the experience is structured the same way, caused by the same source (God), and they call it “the same tree.” Berkeley was fine with that. He said we should speak like ordinary people (“I see the same tree as you”) but think like philosophers (recognizing that “same” is a bit looser than we might assume).
A deeper problem: If you have no idea of a “mind” or “spirit”—since you can only have ideas of things, not of the thing that does the perceiving—how do you even know minds exist? Berkeley admitted this was tricky. He said we have a “notion” of spirit, not an idea. We know our own minds through immediate awareness, not through perceiving them. How satisfying is that? Even Berkeley’s fans have argued about it for centuries.
Is This Crazy?
When Berkeley first published his ideas, most people thought he was joking. A few thought he was insane. Samuel Johnson, a famous writer, supposedly kicked a stone and said, “I refute it thus!”—as if the pain in his toe proved the stone was real and mind-independent.
But Berkeley’s philosophy is harder to dismiss than Johnson thought. The pain in his toe was, after all, an experience in his mind. The stone he saw was a visual experience. The hardness he felt was a tactile experience. In what sense did any of these experiences prove the existence of something outside experience? Johnson was just having more ideas—he didn’t actually step outside his mind to check.
Berkeley’s view has never been popular, but it’s never really gone away either. Philosophers still argue about it. Some think it’s obviously wrong but instructive—it shows us how hard it is to prove that an external world exists. Others think Berkeley was onto something deep: that what we call “the world” is inseparable from our experience of it. A few philosophers today defend a version of Berkeley’s view called “idealism.”
What do you think? You can’t get outside your own mind to check. Every argument you make uses ideas and perceptions. So how would you prove to Berkeley that he’s wrong—without just having more ideas?
This part gets technical, but here’s what it accomplishes: Berkeley’s position forces a choice. You can believe in a world of mind-independent matter, but you’ll have to explain how ideas represent it and how matter causes mental events—two things nobody has ever satisfactorily explained. Or you can give up matter entirely and accept that the world is made of minds and ideas, which comes with its own problems. Neither option is easy. That’s why after 300 years, philosophers are still arguing about it.
Appendices
Key Terms
| Term | What it does in this debate |
|---|---|
| Idea | The basic unit of experience—a color, sound, smell, texture, or thought that exists in a mind and cannot exist without one |
| Matter | The supposed stuff of the physical world that exists independently of minds; Berkeley argues this is an empty concept |
| Mind / Spirit | An active perceiver that has ideas; the only kind of thing that can cause changes in the world, according to Berkeley |
| Esse est percipi | Latin for “to be is to be perceived”; Berkeley’s slogan for the view that things exist only when someone is perceiving them |
| Representationalism | The view that we perceive only our own ideas, which represent (stand for) external objects; Berkeley’s main target |
| Laws of Nature | Regular patterns in our experience, caused by God’s consistent activity; they make prediction and science possible |
Key People
- George Berkeley (1685–1753). An Irish bishop and philosopher who, in his twenties, argued that matter doesn’t exist and that everything is either a mind or an idea in a mind.
- John Locke (1632–1704). An English philosopher who argued that we perceive only ideas in our minds, but that those ideas represent an external world of matter. Berkeley took Locke’s starting point but rejected the conclusion.
- René Descartes (1596–1650). A French philosopher who argued that mind and matter are two completely different kinds of substance, and struggled to explain how they interact. Berkeley found this struggle telling.
Things to Think About
- If you close your eyes and someone else removes the object in front of you, does it “exist” while you had your eyes closed? Your memory says yes. But what does “existed” mean here—existed for whom?
- Could Berkeley’s view work without God? If you remove God from the picture, who or what keeps the world regular and holds things in existence when nobody’s looking?
- When you dream, you experience a world that feels real. Berkeley says the difference is that waking experience is orderly and caused by God. But what if you had an extremely orderly, God-caused dream? Would it still not be real?
- Is it stranger to believe in a world of matter you can never perceive (like the representationalists do) or to believe there’s nothing behind your perceptions (like Berkeley does)? Which one asks you to accept more on faith?
Where This Shows Up
- Movies like The Matrix and Inception explore versions of this question: How do you know the world you experience is real?
- Virtual reality raises Berkeley-like questions. When you put on a VR headset, the “world” you experience only exists while you perceive it. Is your regular world different in kind, or just in degree of stability and detail?
- In science, physicists sometimes talk about “idealism” when discussing whether quantum mechanics means that observation creates reality. (This is controversial—most physicists don’t endorse Berkeley—but the echoes are real.)
- Whenever someone says “That’s just your perception” or “Reality is socially constructed,” they’re brushing up against Berkeley’s territory: the idea that the world might depend on minds.