were quite sure they had attained a certain 'gnosis' - had, more or less successfully, solved the problem of existence; while I was quite sure I had not, and had a pretty strong conviction that the problem was insoluble. And, with Hume and Kant on my side, I could not think myself presumptuous in holding fast by that opinion ... So I took thought, and invented what I conceived to be the appropriate title of 'agnostic'.
Later in his speech, Huxley went on to explain that agnostics have no creed, not even a negative one.
Agnosticism, in fact, is not a creed, but a method, the essence of which lies in the rigorous application of a single principle. . . . Positively the principle may be expressed: In matters of the intellect, follow your reason as far as it will take you, without regard to any other consideration. And negatively: In matters of the intellect, do not pretend that conclusions are certain which are not demonstrated or demonstrable. That I take to be the agnostic faith, which if a man keep whole and undefiled, he shall not be ashamed to look the universe in the face, whatever the future may have in store for him.
To a scientist these are noble words, and one doesn't criticize T. H. Huxley lightly. But Huxley, in his concentration upon the absolute impossibility of proving or disproving God, seems to have been ignoring the shading of probability. The fact that we can neither prove nor disprove the existence of something does not put existence and non-existence on an even footing. I don't think Huxley would disagree, and I suspect that when he appeared to do so he was bending over backwards to concede a point, in the interests of securing another one. We have all done this at one time or another.
Contrary to Huxley, I shall suggest that the existence of God is a scientific hypothesis like any other. Even if hard to test in practice, it belongs in the same TAP or temporary agnosticism box as the controversies over the Permian and Cretaceous extinctions. God's existence or non-existence is a scientific fact about the universe, discoverable in principle if not in practice. If he existed and chose to reveal it, God himself could clinch the argument, noisily and unequivocally, in his favour. And even if God's existence is never proved or disproved with certainty one way or the other, available evidence and reasoning may yield an estimate of probability far from 50 per cent.
Let us, then, take the idea of a spectrum of probabilities seriously, and place human judgements about the existence of God along it, between two extremes of opposite certainty. The spectrum is continuous, but it can be represented by the following seven milestones along the way.
1. Strong theist. 100 per cent probability of God. In the words of C. G. Jung, 'I do not believe, I know.'
2. Very high probability but short of 100 per cent. De facto theist. 'I cannot know for certain, but I strongly believe in God and live my life on the assumption that he is there.'
3. Higher than 50 per cent but not very high. Technically agnostic but leaning towards theism. 'I am very uncertain, but I am inclined to believe in God.'
4. Exactly 50 per cent. Completely impartial agnostic. 'God's existence and non-existence are exactly equiprobable.'
5. Lower than 50 per cent but not very low. Technically agnostic but leaning towards atheism. 'I don't know whether God exists but I'm inclined to be sceptical.'
6. Very low probability, but short of zero. De facto atheist. 'I cannot know for certain but I think God is very improbable, and I live my life on the assumption that he is not there.'
7. Strong atheist. 'I know there is no God, with the same conviction as Jung "knows" there is one.'
I'd be surprised to meet many people in category 7, but I include it for symmetry with category 1, which is well populated. It is in the nature of faith that one is capable, like Jung, of holding a belief without adequate reason to do so (Jung also believed that particular books on his shelf spontaneously exploded with a loud bang). Atheists do not have faith; and reason alone could not propel one to total conviction that anything definitely does not exist. Hence category 7 is in practice rather emptier than its opposite number, category 1, which has many devoted inhabitants. I count myself in category 6, but leaning towards 7-1 am agnostic only to the extent that I am agnostic about fairies at the bottom of the garden.
The spectrum of probabilities works well for TAP (temporary agnosticism in practice). It is superficially tempting to place PAP (permanent agnosticism in principle) in the middle of the spectrum, with a 50 per cent probability of God's existence, but this is not correct. PAP agnostics aver that we cannot say anything, one way or the other, on the question of whether or not God exists. The question, for PAP agnostics, is in principle unanswerable, and they should strictly refuse to place themselves anywhere on the spectrum of probabilities. The fact that I cannot know whether your red is the same as my green doesn't make the probability 50 per cent. The proposition on offer is too meaningless to be dignified with a probability. Nevertheless, it is a common error, which we shall meet again, to leap from the premise that the question of God's existence is in principle unanswerable to the conclusion that his existence and his non-existence are equiprobable.
Another way to express that error is in terms of the burden of proof, and in this form it is pleasingly demonstrated by Bertrand Russell's parable of the celestial teapot.31
Many orthodox people speak as though it were the business of sceptics to disprove received dogmas rather than of dogmatists to prove them. This is, of course, a mistake. If I were to suggest that between the Earth and Mars there is a china teapot revolving about the sun in an elliptical orbit, nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes. But if I were to go on to say that, since my assertion cannot be disproved, it is intolerable presumption on the part of human reason to doubt it, I should rightly be thought to be talking nonsense. If, however, the existence of such a teapot were affirmed in ancient books, taught as the sacred truth every Sunday, and instilled into the minds of children at school, hesitation to believe in its existence would become a mark of eccentricity and entitle the doubter to the attentions of the psychiatrist in an enlightened age or of the Inquisitor in an earlier time.
We would not waste time saying so because nobody, so far as I know, worships teapots; * but, if pressed, we would not hesitate to declare our strong belief that there is positively no orbiting teapot. Yet strictly we should all be teapot agnostics: we cannot prove, for sure, that there is no celestial teapot. In practice, we move away from teapot agnosticism towards a-teapotism.
* Perhaps I spoke too soon. The Independent on Sunday of 5 June 2005 carried the following item: 'Malaysian officials say religious sect which built sacred teapot the size of a house has flouted planning regulations.' See also BBC News at http://news.bbc.co.Uk/2/hi/asia-pacific/4692039.stm.
A friend, who was brought up a Jew and still observes the sabbath and other Jewish customs out of loyalty to his heritage, describes himself as a 'tooth fairy agnostic'. He regards God as no more probable than the tooth fairy. You can't disprove either hypothesis, and both are equally improbable. He is an a-theist to exactly the same large extent that he is an a-fairyist. And agnostic about both, to the same small extent.
Russell's teapot, of course, stands for an infinite number of things whose existence is conceivable and cannot be disproved. That great American lawyer Clarence Darrow said, 'I don't believe in God as I don't believe in Mother Goose.' The journalist Andrew Mueller is of the opinion that pledging yourself to any particular religion 'is no more or less weird than choosing to believe that the world is rhombus-shaped, and borne through the cosmos in the pincers of two enormous green lobsters called Esmerelda and Keith'.32 A philosophical favourite is the invisible, intangible, inaudible unicorn, disproof of which is attempted yearly by the children at Camp Quest.* A popular deity on the Internet at present
- and as undisprovable as Yahweh or any other - is the Flying Spaghetti Monster, who, many claim, has touched them with his noodly appendage.33 I am delighted to see tha
t the Gospel of the Flying Spaghetti Monster has now been published as a book,34 to great acclaim. I haven't read it myself, but who needs to read a gospel when you just know it's true? By the way, it had to happen
- a Great Schism has already occurred, resulting in the Reformed Church of the Flying Spaghetti Monster.35
The point of all these way-out examples is that they are undisprovable, yet nobody thinks the hypothesis of their existence is on an even footing with the hypothesis of their non-existence. Russell's point is that the burden of proof rests with the believers, not the non-believers. Mine is the related point that the odds in favour of the teapot (spaghetti monster / Esmerelda and Keith / unicorn etc.) are not equal to the odds against.
* Camp Quest takes the American institution of the summer camp in an entirely admirable direction. Unlike other summer camps that follow a religious or scouting ethos, Camp Quest, founded by Edwin and Helen Kagin in Kentucky, is run by secular humanists, and the children are encouraged to think sceptically for themselves while having a very good time with all the usual outdoor activities (www.camp-quest.org). Other Camp Quests with a similar ethos have now sprung up in Tennessee, Minnesota, Michigan, Ohio and Canada.
The fact that orbiting teapots and tooth fairies are undisprovable is not felt, by any reasonable person, to be the kind of fact that settles any interesting argument. None of us feels an obligation to disprove any of the millions of far-fetched things that a fertile or facetious imagination might dream up. I have found it an amusing strategy, when asked whether I am an atheist, to point out that the questioner is also an atheist when considering Zeus, Apollo, Amon Ra, Mithras, Baal, Thor, Wotan, the Golden Calf and the Flying Spaghetti Monster. I just go one god further.
All of us feel entitled to express extreme scepticism to the point of outright disbelief - except that in the case of unicorns, tooth fairies and the gods of Greece, Rome, Egypt and the Vikings, there is (nowadays) no need to bother. In the case of the Abrahamic God, however, there is a need to bother, because a substantial proportion of the people with whom we share the planet do believe strongly in his existence. Russell's teapot demonstrates that the ubiquity of belief in God, as compared with belief in celestial teapots, does not shift the burden of proof in logic, although it may seem to shift it as a matter of practical politics. That you cannot prove God's non-existence is accepted and trivial, if only in the sense that we can never absolutely prove the non-existence of anything. What matters is not whether God is disprovable (he isn't) but whether his existence is probable. That is another matter. Some undisprovable things are sensibly judged far less probable than other undisprovable things. There is no reason to regard God as immune from consideration along the spectrum of probabilities. And there is certainly no reason to suppose that, just because God can be neither proved nor disproved, his probability of existence is 50 per cent. On the contrary, as we shall see.
NOMA
Just as Thomas Huxley bent over backwards to pay lip service to completely impartial agnosticism, right in the middle of my seven-stage spectrum, theists do the same thing from the other direction, and for an equivalent reason. The theologian Alister McGrath makes it the central point of his book Hawkins' God: Genes, Memes and the Origin of Life. Indeed, after his admirably fair summary of my scientific works, it seems to be the only point in rebuttal that he has to offer: the undeniable but ignominiously weak point that you cannot disprove the existence of God. On page after page as I read McGrath, I found myself scribbling 'teapot' in the margin. Again invoking T. H. Huxley, McGrath says, 'Fed up with both theists and atheists making hopelessly dogmatic statements on the basis of inadequate empirical evidence, Huxley declared that the God question could not be settled on the basis of the scientific method.'
McGrath goes on to quote Stephen Jay Gould in similar vein: 'To say it for all my colleagues and for the umpteenth millionth time (from college bull sessions to learned treatises): science simply cannot (by its legitimate methods) adjudicate the issue of God's possible superintendence of nature. We neither affirm nor deny it; we simply can't comment on it as scientists.' Despite the confident, almost bullying, tone of Gould's assertion, what, actually, is the justification for it? Why shouldn't we comment on God, as scientists? And why isn't Russell's teapot, or the Flying Spaghetti Monster, equally immune from scientific scepticism? As I shall argue in a moment, a universe with a creative superintendent would be a very different kind of universe from one without. Why is that not a scientific matter?
Gould carried the art of bending over backwards to positively supine lengths in one of his less admired books, Rocks of Ages. There he coined the acronym NOMA for the phrase 'non-overlapping magisterial
The net, or magisterium, of science covers the empirical realm: what is the universe made of (fact) and why does it work this way (theory). The magisterium of religion extends over questions of ultimate meaning and moral value. These two magisteria do not overlap, nor do they encompass all inquiry (consider, for example, the magisterium of art and the meaning of beauty). To cite the old cliches, science gets the age of rocks, and religion the rock of ages; science studies how the heavens go, religion how to go to heaven.
This sounds terrific - right up until you give it a moment's thought. What are these ultimate questions in whose presence religion is an honoured guest and science must respectfully slink away?
Martin Rees, the distinguished Cambridge astronomer whom I have already mentioned, begins his book Our Cosmic Habitat by posing two candidate ultimate questions and giving a NOMA-friendly answer. 'The pre-eminent mystery is why anything exists at all. What breathes life into the equations, and actualized them in a real cosmos? Such questions lie beyond science, however: they are the province of philosophers and theologians.' I would prefer to say that if indeed they lie beyond science, they most certainly lie beyond the province of theologians as well (I doubt that philosophers would thank Martin Rees for lumping theologians in with them). I am tempted to go further and wonder in what possible sense theologians can be said to have a province. I am still amused when I recall the remark of a former Warden (head) of my Oxford college. A young theologian had applied for a junior research fellowship, and his doctoral thesis on Christian theology provoked the Warden to say, 'I have grave doubts as to whether it's a subject at all.'
What expertise can theologians bring to deep cosmological questions that scientists cannot? In another book I recounted the words of an Oxford astronomer who, when I asked him one of those same deep questions, said: 'Ah, now we move beyond the realm of science. This is where I have to hand over to our good friend the chaplain.' I was not quick-witted enough to utter the response that I later wrote: 'But why the chaplain? Why not the gardener or the chef?' Why are scientists so cravenly respectful towards the ambitions of theologians, over questions that theologians are certainly no more qualified to answer than scientists themselves?
It is a tedious cliche (and, unlike many cliches, it isn't even true) that science concerns itself with how questions, but only theology is equipped to answer why questions. What on Earth is a why question? Not every English sentence beginning with the word 'why' is a legitimate question. Why are unicorns hollow? Some questions simply do not deserve an answer. What is the colour of abstraction? What is the smell of hope? The fact that a question can be phrased in a grammatically correct English sentence doesn't make it meaningful, or entitle it to our serious attention. Nor, even if the question is a real one, does the fact that science cannot answer it imply that religion can.
Perhaps there are some genuinely profound and meaningful questions that are forever beyond the reach of science. Maybe quantum theory is already knocking on the door of the unfathomable. But if science cannot answer some ultimate question, what makes anybody think that religion can? I suspect that neither the Cambridge nor the Oxford astronomer really believed that theologians have any expertise that enables them to answer questions that are too deep for science. I suspect that both astronomers were, yet again, be
nding over backwards to be polite: theologians have nothing worthwhile to say about anything else; let's throw them a sop and let them worry away at a couple of questions that nobody can answer and maybe never will. Unlike my astronomer friends, I don't think we should even throw them a sop. I have yet to see any good reason to suppose that theology (as opposed to biblical history, literature, etc.) is a subject at all.
Similarly, we can all agree that science's entitlement to advise us on moral values is problematic, to say the least. But does Gould really want to cede to religion the right to tell us what is good and what is bad? The fact that it has nothing else to contribute to human wisdom is no reason to hand religion a free licence to tell us what to do. Which religion, anyway? The one in which we happen to have been brought up? To which chapter, then, of which book of the Bible should we turn - for they are far from unanimous and some of them are odious by any reasonable standards. How many literalists have read enough of the Bible to know that the death penalty is prescribed for adultery, for gathering sticks on the sabbath and for cheeking your parents? If we reject Deuteronomy and Leviticus (as all enlightened moderns do), by what criteria do we then decide which of religion's moral values to accept} Or should we pick and choose among all the world's religions until we find one whose moral teaching suits us? If so, again we must ask, by what criterion do we choose? And if we have independent criteria for choosing among religious moralities, why not cut out the middle man and go straight for the moral choice without the religion? I shall return to such questions in Chapter 7.
I simply do not believe that Gould could possibly have meant much of what he wrote in Rocks of Ages. As I say, we have all been guilty of bending over backwards to be nice to an unworthy but powerful opponent, and I can only think that this is what Gould was doing. It is conceivable that he really did intend his unequivocally strong statement that science has nothing whatever to say about the question of God's existence: 'We neither affirm nor deny it; we simply can't comment on it as scientists.' This sounds like agnosticism of the permanent and irrevocable kind, full-blown PAP. It implies that science cannot even make probability judgements on the question. This remarkably widespread fallacy - many repeat it like a mantra but few of them, I suspect, have thought it through - embodies what I refer to as 'the poverty of agnosticism'. Gould, by the way, was not an impartial agnostic but strongly inclined towards de facto atheism. On what basis did he make that judgement, if there is nothing to be said about whether God exists? The God Hypothesis suggests that the reality we inhabit also contains a supernatural agent who designed the universe and - at least in many versions of the hypothesis - maintains it and even intervenes in it with miracles, which are temporary violations of his own otherwise grandly immutable laws. Richard Swinburne, one of Britain's leading theologians, is surprisingly clear on the matter in his book Is There a God?: