Why there is no God
Richard Dawkins

People who claim to have seen God are delusional and Thomas Aquinas's logic was flawed, our correspondent argues in an extract from his bestselling book

One of the cleverer and more mature of my undergraduate contemporaries, who was deeply religious, went camping in the Scottish isles. In the middle of the night he and his girlfriend were woken in their tent by the voice of the devil — Satan himself; there could be no possible doubt: the voice was in every sense diabolical. My friend would never forget this horrifying experience, and it was one of the factors that later drove him to be ordained. My youthful self was impressed by his story, and I recounted it to a gathering of zoologists relaxing in the Rose and Crown Inn, Oxford. Two of them happened to be experienced ornithologists, and they roared with laughter. “Manx shearwater!” they shouted in delighted chorus. One of them added that the diabolical shrieks and cackles of this species have earned it, in various parts of the world and various languages, the local nickname “Devil Bird”.
The argument from personal experience is the one that is most convincing to those who claim to have had one. But it is the least convincing to anyone else, especially anyone knowledgeable about psychology. Many people believe in God because they believe they have seen a vision of him — or of an angel or a virgin in blue — with their own eyes. Or he speaks to them inside their heads.

You say you have experienced God directly? Well, some people have experienced a pink elephant, but that probably doesn’t impress you.

Peter Sutcliffe, the Yorkshire Ripper, distinctly heard the voice of Jesus telling him to kill women, and he was locked up for life. George W. Bush says that God told him to invade Iraq (a pity God didn’t vouchsafe him a revelation that there were no weapons of mass destruction).

Individuals in asylums think they are Napoleon or Charlie Chaplin, or that the entire world is conspiring against them, or that they can broadcast their thoughts into other people’s heads. We humour them but don’t take their internally revealed beliefs seriously, mostly because not many people share them.

Religious experiences are different only in that the people who claim them are numerous. Sam Harris was not being overly cynical when he wrote, in The End of Faith: “We have names for people who have many beliefs for which there is no rational justification. When their beliefs are extremely common we call them ‘religious’; otherwise, they are likely to be called ‘mad’, ‘psychotic’ or ‘ delusional’... Clearly there is sanity in numbers. And yet, it is merely an accident of history that it is considered normal in our society to believe that the Creator of the universe can hear your thoughts, while it is demonstrative of mental illness to believe that he is communicating with you by having the rain tap in Morse code on your bedroom window. And so, while religious people are not generally mad, their core beliefs absolutely are.”

The human brain runs first-class simulation software. Our eyes don’t present to our brains a faithful photograph of what is out there, or an accurate movie of what is going on through time. Our brains construct a continuously updated model: updated by coded pulses chattering along the optic nerve, but constructed nevertheless. Optical illusions are vivid reminders of this. A major class of illusions, of which the Necker Cube is an example, arise because the sense data that the brain receives are compatible with two alternative models of reality. The brain, having no basis for choosing between them, alternates, and we experience a series of flips from one internal model to the other. The picture we are looking at appears, almost literally, to flip over and become something else.

The simulation software in the brain is especially adept at constructing faces and voices. I have on my windowsill a plastic mask of Einstein. When seen from the front, it looks like a solid face; not surprisingly. What is surprising is that, when seen from behind — the hollow side — it also looks like a solid face, and our perception of it is very odd indeed. As the viewer moves around, the face seems to follow — and not in the weak, unconvincing sense that the Mona Lisa’s eyes are said to follow you. The hollow mask really really looks as though it is moving.

People who haven’t previously seen the illusion gasp with amazement. Even stranger, if the mask is mounted on a slowly rotating turntable, it appears to turn in the correct direction when you are looking at the solid side, but in the opposite direction when the hollow side comes into view. The result is that, when you watch the transition from one side to the other, the coming side appears to “eat” the going side. It is a stunning illusion, well worth going to some trouble to see. Sometimes you can get surprisingly close to the hollow face and still not see that it is really hollow. When you do see it, again there is a sudden flip, which may be reversible.

Why does it happen? There is no trick in the construction of the mask. Any hollow mask will do it. The trickery is all in the brain of the beholder. The internal simulating software receives data indicating the presence of a face, perhaps nothing more than a pair of eyes, a nose and a mouth in approximately the right places. Having received these sketchy clues, the brain does the rest. The face simulation software kicks into action and it constructs a fully solid model of a face, even though the reality presented to the eyes is a hollow mask. The illusion of rotation in the wrong direction comes about because (it’s quite hard, but if you think it through carefully you will confirm it) reverse rotation is the only way to make sense of the optical data when a hollow mask rotates while being perceived to be a solid mask. It is like the illusion of a rotating radar dish that you sometimes see at airports. Until the brain flips to the correct model of the radar dish, an incorrect model is seen rotating in the wrong direction but in a weirdly cockeyed way.

I say all this just to demonstrate the formidable power of the brain’s simulation software. It is well capable of constructing “visions” and “visitations” of the utmost veridical power. To simulate a ghost or an angel or a Virgin Mary would be child’s play to software of this sophistication.

Once, as a child, I heard a ghost: a male voice murmuring, as if in recitation or prayer. I could almost, but not quite, make out the words, which seemed to have a serious, solemn timbre. I had been told stories of priest holes in ancient houses, and I was a little frightened. But I got out of bed and crept up on the source of the sound. As I got closer, it grew louder, and then suddenly it “flipped” inside my head. I was now close enough to discern what it really was. The wind, gusting through the keyhole, was creating sounds which the simulation software in my brain had used to construct a model of male speech, solemnly intoned.

Had I been a more impressionable child, it is possible that I would have “heard” not just unintelligible speech but particular words and even sentences. And had I been both impressionable and religiously brought-up, I wonder what words the wind might have spoken.

On another occasion, when I was about the same age, I saw a giant round face gazing, with unspeakable malevolence, out through the window of an otherwise ordinary house in a seaside village. In trepidation, I approached until I was close enough to see what it really was: just a vaguely face-like pattern created by the chance fall of the curtains. The face itself, and its evil mien, had been constructed in my fearful child’s brain. On September 11, 2001, pious people thought they saw the face of Satan in the smoke rising from the twin towers, a superstition backed by a photograph which was published on the internet and widely circulated.

Constructing models is something the human brain is very good at. When we are asleep it is called dreaming; when we are awake we call it imagination or, when it is exceptionally vivid, hallucination. Children who have imaginary friends sometimes see them clearly, exactly as if they were real. If we are gullible, we don’t recognise hallucination or lucid dreaming for what it is and we claim to have seen or heard a ghost; or an angel; or God; or — especially if we happen to be young, female and Catholic — the Virgin Mary. Such visions and manifestations are certainly not good grounds for believing that ghosts or angels, gods or virgins, are actually there.

On the face of it mass visions, such as the report that 70,000 pilgrims at Fatima in Portugal in 1917 saw the sun “tear itself from the heavens and come crashing down upon the multitude”, are harder to write off.

It is not easy to explain how 70,000 people could share the same hallucination. But it is even harder to accept that it really happened without the rest of the world, outside Fatima, seeing it too — and not just seeing it, but feeling it as the catastrophic destruction of the solar system, including acceleration forces sufficient to hurl everybody into space. David Hume’s pithy test for a miracle comes irresistibly to mind: “No testimony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous than the fact which it endeavours to establish.” It may seem improbable that 70,000 people could simultaneously be deluded, or could simultaneously collude in a mass lie. Or that history is mistaken in recording that 70,000 people claimed to see the sun dance. Or that they all simultaneously saw a mirage (they had been persuaded to stare at the sun, which can’t have done much for their eyesight). But any of those apparent improbabilities is far more probable than the alternative: that the Earth was suddenly yanked sideways in its orbit, and the solar system destroyed, with nobody outside Fatima noticing. I mean, Portugal is not that isolated (although admittedly my wife’s parents once stayed in a Paris hotel called the Hotel de l’Univers et du Portugal).

That is really all that needs to be said about personal “experiences” of gods or other religious phenomena. If you’ve had such an experience, you may well find yourself believing firmly that it was real. But don’t expect the rest of us to take your word for it, especially if we have the slightest familiarity with the brain and its powerful workings.

© Richard Dawkins 2006
The God Delusion is published by Bantam Press at £20. Available from Times BooksFirst at £17.99, free p&p. Call 0870 1608080

THOMAS AQUINAS, THE FIVE PROOFS, AND HOW HE GOT IT WRONG

The five “proofs” asserted by Thomas Aquinas in the 13th century don’t prove anything, and are easily — though I hesitate to say so, given his eminence — exposed as vacuous. The first three are just different ways of saying the same thing, and they can be considered together. All involve an infinite regress — the answer to a question raises a prior question, and so on ad infinitum.

1 The Unmoved Mover

Nothing moves without a prior mover. This leads us to an infinite regress, from which the only escape is God. Something had to make the first move, and that something we call God.

2 The Uncaused Cause

Nothing is caused by itself. Every effect has a prior cause, and again we are pushed back into infinite regress. This has to be terminated by a first cause, which we call God.

3 The Cosmological Argument

There must have been a time when no physical things existed. But, since physical things exist now, there must have been something non-physical to bring them into existence, and that something we call God.

All three of these arguments rely upon the idea of an infinite regress and invoke God to terminate it. They make the entirely unwarranted assumption that God himself is immune to the regress. Even if we allow the dubious luxury of arbitrarily conjuring up a terminator to an infinite regress and giving it a name, simply because we need one, there is absolutely no reason to endow that terminator with any of the properties normally ascribed to God; omnipotence, omniscience, goodness, creativity of design, to say nothing of such human attributes as listening to prayers, forgiving sins and reading innermost thoughts.

Edward Lear’s Nonsense Recipe for Crumboblious Cutlets invites us to “Procure some strips of beef, and having cut them into the smallest possible pieces, proceed to cut them still smaller, eight or perhaps nine times.” Some regresses do reach a natural terminator. Scientists used to wonder what would happen if you could dissect, say, gold into the smallest possible pieces. Why shouldn’t you cut one of those pieces in half and produce an even smaller smidgin of gold? The regress in this case is decisively terminated by the atom. The smallest possible piece of gold is a nucleus consisting of exactly 79 protons and a slightly larger number of neutrons, surrounded by a swarm of 79 electrons. If you “cut” gold any further than the level of the single atom, whatever else you get it is not gold. The atom provides a natural terminator to the Crumboblious Cutlets type of regress. It is by no means clear that God provides a natural terminator to the regresses of Aquinas.

Let’s move on down Aquinas’s list.

4 The Argument from Degree

We notice that things in the world differ. There are degrees of, say, goodness or perfection. But we judge these degrees only by comparison with a maximum. Humans can be both good and bad, so the maximum goodness cannot rest in us. Therefore there must be some other maximum to set the standard for perfection, and we call that maximum God.

That’s an argument? You might as well say, people vary in smelliness but we can make the comparison only by reference to a perfect maximum of conceivable smelliness. Therefore there must exist a pre-eminently peerless stinker, and we call him God. Or substitute any dimension of comparison you like and derive an equivalently fatuous conclusion.

5 The Teleological Argument, or Argument from Design

Things in the world, especially living things, look as though they have been designed. Nothing that we know looks designed unless it is designed. Therefore there must have been a designer, and we call him God. Aquinas himself used the analogy of an arrow moving towards a target, but a modern heat-seeking anti-aircraft missile would have suited his purpose better.

The argument from design is the only one still in regular use today, and it still sounds to many like the ultimate knockdown argument. The young Darwin was impressed by it when, as a Cambridge undergraduate, he read it in William Paley’s Natural Theology. Unfortunately for Paley, the mature Darwin blew it out of the water. There has probably never been a more devastating rout of popular belief by clever reasoning than Charles Darwin’s destruction of the argument from design. It was so unexpected.

Thanks to Darwin, it is no longer true to say that nothing that we know looks designed unless it is designed. Evolution by natural selection produces an excellent simulacrum of design, mounting prodigious heights of complexity and elegance. And among these eminences of pseudo-design are nervous systems which — among their more modest accomplishments — manifest goal-seeking behaviour that, even in a tiny insect, resembles a sophisticated heat-seeking missile more than a simple arrow on target.