For the first half of geological time our ancestors were bacteria. Most creatures still are bacteria, and each one of our trillions of cells is a colony of bacteria.

You could give Aristotle a tutorial. And you could thrill him to the core of his being. Aristotle was an encyclopedic polymath, an all time intellect. Yet not only can you know more than him about the world, you also can have a deeper understanding of how everything works. Such is the privilege of living after Newton, Darwin, Einstein, Planck, Watson, Crick and their colleagues.

I don't want to sound callous. I mean, even if I have nothing to offer, that doesn't matter, because that still doesn't mean that what anybody else has to offer therefore has to be true.

It is hard to believe that this simple truth is not understood by those leaders who forbid their followers to use effective contraceptive methods. They express a preference for 'natural' methods of population limitation, and a natural method is exactly what they are going to get. It is called starvation.

One feature of our own society that seems decidedly anomalous is the matter of sexual advertisement. As we have seen, it is strongly to be expected on evolutionary grounds that, where the sexes differ, it should be the males that advertise and the females that are drab. Modern western man is undoubtedly exceptional in this respect. It is of course true that some men dress flamboyantly and some women dress drably but, on average, there can be no doubt that in our society the equivalent of the peacock's tail is exhibited by the female, not by the male. Women paint their faces and glue on false eyelashes. Apart from special cases, like actors, men do not. Ch. 9. Battle of the Sexes

Darwin made it possible to be an intellectually fulfilled atheist.

However many ways there may be of being alive, it is certain that there are vastly more ways of being dead.

Human vanity cherishes the absurd notion that our species is the final goal of evolution.

To explain the origin of the DNA/protein machine by invoking a supernatural Designer is to explain precisely nothing, for it leaves unexplained the origin of the Designer.

Our subjective judgment of what seems like a good bet is irrelevant to what is actually a good bet.

Contrary to earlier prejudices, there is nothing inherently progressive about evolution.

It is generally characteristic of arms races, including human ones, that although all would be better off if none of them escalated, so long as one of them escalates none can afford not to.

There has been progress in design, but not progress in accomplishment.

The successful scientist and the raving crank are separated by the quality of their inspirations. But I suspect that this amounts, in practice, to a difference, not so much in ability to notice analogies as in ability to reject foolish analogies and pursue helpful ones.

There are people in the world who desperately want not to have to believe in Darwinism.

I would mind more if I could claim that The Selfish Gene had become severely outmoded and superseded. Unfortunately (from one point of view) I cannot. Details have changed and factual examples burgeoned mightily. But, with an exception that I shall discuss in a moment, there is little in the book that I would rush to take back now, or apologize for.

Just because science so far has failed to explain something, such as consciousness, to say it follows that the facile, pathetic explanations which religion has produced somehow by default must win the argument is really quite ridiculous.

In particular, it is certainly wrong to condemn poor old Homo sapiens as the only species to kill his own kind, the only inheritor of the mark of Cain, and similar melodramatic charges. Whether a naturalist stresses the violence or the restraint of animal aggression depends partly on the kinds of animals he is used to watching, and partly on his evolutionary preconceptions-Lorenz is, after all, a 'good of the species' man. Even if it has been exaggerated, the gloved fist view of animal fights seems to have at least some truth. Superficially this looks like a form of altruism. The selfish gene theory must face up to the difficult task of explaining it. Why is it that animals do not go all out to kill rival members of their species at every possible opportunity?

Just because science can't in practice explain things like the love that motivates a poet to write a sonnet, that doesn't mean that religion can. It's a simple and logical fallacy to say, 'If science can't do something, therefore religion can'.

The first cause cannot have been an intelligence, let alone an intelligence that answers prayers and enjoys being worshiped. Intelligent, creative, complex, statistically improbable things come late into the universe, as the product of evolution or some other process of gradual escalation from simple beginnings. They come late into the universe and therefore cannot be responsible for designing it. "Why There Almost Certainly Is No God", The Huffington Post, 23/10/2006

But if you can breed cattle for milk yield, horses for running speed, and dogs for herding skill, why on Earth should it be impossible to breed humans for mathematical, musical or athletic ability? Objections such as "these are not one-dimensional abilities" apply equally to cows, horses and dogs and never stopped anybody in practice. I wonder whether, some 60 years after Hitler's death, we might at least venture to ask what the moral difference is between breeding for musical ability and forcing a child to take music lessons. Or why it is acceptable to train fast runners and high jumpers but not to breed them. I can think of some answers, and they are good ones, which would probably end up persuading me. But hasn't the time come when we should stop being frightened even to put the question? From the Afterword, The Herald

Even the constantly reiterated insistence that we are miserable offenders, born in sin, is a kind of inverted arrogance: such vanity, to presume that our moral conduct has some sort of cosmic significance, as though the Creator of the Universe wouldn't have better things to do than tot up our black marks and our brownie points. The universe is all concerned with me. Is that not the arrogance that passeth all understanding? The Intellectual and Moral Courage of Atheism

Ignorance, to a scientist, is an itch that begs to be pleasurably scratched. Ignorance, if you are a theologian, is something to be washed away by shamelessly making something up.

We are not arrogant, not hubristic, to celebrate the sheer bulk and detail of what we know through science. We are simply telling the honest and irrefutable truth. Also honest is the frank admission of how much we don't yet know - how much more work remains to be done. That is the very antithesis of hubristic arrogance. Science combines a massive contribution, in volume and detail, of what we do know with humility in proclaiming what we don't. Religion, by embarrassing contrast, has contributed literally zero to what we know, combined with huge hubristic confidence in the alleged facts it has simply made up.

It takes intellectual courage to kick yourself out of your emotional incredulity and persuade yourself that there is no other rational choice.

Atheists have the intellectual courage to accept reality for what it is: wonderfully and shockingly explicable. As an atheist, you have the moral courage to live to the full the only life you're ever going to get: to fully inhabit reality, rejoice in it, and do your best finally to leave it better than you found it.

Even sticking to the higher plane of love, is it so very obvious that you can't love more than one person? We seem to manage it with parental love (parents are reproached if they don't at least pretend to love all their children equally), love of books, of food, of wine (love of Chateau Margaux does not preclude love of a fine Hock, and we don't feel unfaithful to the red when we dally with the white), love of composers, poets, holiday beaches, friends . . . why is erotic love the one exception that everybody instantly acknowledges without even thinking about it?

I'm not one of those who wants to stop Christian traditions. This is historically a Christian country. I'm a cultural Christian the same way as many of my friends call themselves cultural Jews or cultural Muslims. So, yes, I love singing carols along with everybody else. I'm not one of those who wants to purge our society of our Christian history.

Gravity is not a version of the truth. It is the truth. Anybody who doubts it is invited to jump out of a tenth-floor window.

It would be deeply depressing if the only way children could get moral values was from religion. Either from scripture, and God knows we don't want them to get it from scripture, I mean, just look at scripture. Or, from being afraid of God, being intimidated by God. Anybody who is good for only those two reasons is not really being good at all. Why not teach children things like the Golden Rule, do as you would be done by, how would you like it if other children did that to you, so why do you do it to them... I think it's depressing that anybody should suggest that you actually need God in order to be moral. I would hope that our morals come from a better source than that, and therefore they are genuinely moral rather than based on outmoded scripture, or based on fear.

It's almost impossible to say anything against Islam in this country, because you are accused of being racist or Islamophobic.

We should be offended when children are denied a proper education. We should be offended when children are told they will spend eternity in hell. We should be offended when medical science, for example stem-cell research, is compromised by the bigoted opinions of powerful and above all well-financed ignoramuses. We should be offended when voodoo, of all kinds, is given equal weight to science. We should be offended by hymen reconstruction surgery. We should be offended by 'female circumcision', euphemism for genital mutilation. We should be offended by stoning.

Evolution is a fact. Beyond reasonable doubt, beyond serious doubt, beyond sane, informed, intelligent doubt, beyond doubt evolution is a fact. The evidence for evolution is at least as strong as the evidence for the Holocaust, even allowing for eye witnesses to the Holocaust. It is the plain truth that we are cousins of chimpanzees, somewhat more distant cousins of monkeys, more distant cousins still of aardvarks and manatees, yet more distant cousins of bananas and turnips... continue the list as long as desired.

It's obvious that in an intelligent educated audience such as this university, I stress this university. Who saw fit to give them accreditation? At Randolph-Macon Woman's College, (23 October 2006) Broadcasted by C-SPAN2

If it's really true, that the museum at Liberty University has dinosaur fossils which are labelled as being 3000 years old, then that is an educational disgrace. It is debauching the whole idea of a university, and I would strongly encourage any members of Liberty University who may be here...to leave and go to a proper university.

Bush and bin Laden are really on the same side: the side of faith and violence against the side of reason and discussion. Both have implacable faith that they are right and the other is evil. Each believes that when he dies he is going to heaven. Each believes that if he could kill the other, his path to paradise in the next world would be even swifter. The delusional "next world" is welcome to both of them. This world would be a much better place without either of them.

Faith is the great cop-out, the great excuse to evade the need to think and evaluate evidence. Faith is belief in spite of, even perhaps because of, the lack of evidence.

It is often said, mainly by the 'no-contests', that although there is no positive evidence for the existence of God, nor is there evidence against his existence. So it is best to keep an open mind and be agnostic. At first sight that seems an unassailable position, at least in the weak sense of Pascal's wager. But on second thoughts it seems a cop-out, because the same could be said of Father Christmas and tooth fairies. There may be fairies at the bottom of the garden. There is no evidence for it, but you can't prove that there aren't any, so shouldn't we be agnostic with respect to fairies?

You see, if you say something positive like the whole of life - all living things - is descended from a single common ancestor which lived about 4,000 million years ago and that we are all cousins, well that is an exceedingly important and true thing to say and that is what I want to say. Somebody who is religious sees that as threatening and so I am represented as attacking religion, and I am forced into responding to their reaction. But you do not have to see my main purpose as attacking religion. Certainly I see the scientific view of the world as incompatible with religion, but that is not what is interesting about it. It is also incompatible with magic, but that also is not worth stressing. What is interesting about the scientific world view is that it is true, inspiring, remarkable and that it unites a whole lot of phenomena under a single heading. And that is what is so exciting for me.

What worries me about religion is that it teaches people to be satisfied with not understanding the world they live in.

The wheel may be one of those cases where the engineering solution can be seen in plain view, yet be unattainable in evolution because it lies on the other side of a deep valley, cutting unbridgeably across the massif of Mount Improbable.

The popularity of the paranormal, oddly enough, might even be grounds for encouragement. I think that the appetite for mystery, the enthusiasm for that which we do not understand, is healthy and to be fostered. It is the same appetite which drives the best of true science, and it is an appetite which true science is best qualified to satisfy.

It is fashionable to wax apocalyptic about the threat to humanity posed by the AIDS virus, "mad cow" disease, and many others, but I think a case can be made that faith is one of the world's great evils, comparable to the smallpox virus but harder to eradicate.

More generally it is completely unrealistic to claim, as Gould and many others do, that religion keeps itself away from science's turf, restricting itself to morals and values. A universe with a supernatural presence would be a fundamentally and qualitatively different kind of universe from one without. The difference is, inescapably, a scientific difference. Religions make existence claims, and this means scientific claims.

For his purposes (and mine), scientific medicine is defined as the set of practices which submit themselves to the ordeal of being tested. Alternative medicine is defined as that set of practices which cannot be tested, refuse to be tested, or consistently fail tests. If a healing technique is demonstrated to have curative properties in properly controlled double-blind trials, it ceases to be alternative. It simply, as Diamond explains, becomes medicine. Conversely, if a technique devised by the President of the Royal College of Physicians consistently fails in double-blind trials, it will cease to be a part of 'orthodox' medicine. Whether it will then become 'alternative' will depend upon whether it is adopted by a sufficiently ambitious quack (there are always sufficiently gullible patients).

Many of us saw religion as harmless nonsense. Beliefs might lack all supporting evidence but, we thought, if people needed a crutch for consolation, where's the harm? September 11th changed all that. Revealed faith is not harmless nonsense, it can be lethally dangerous nonsense. Dangerous because it gives people unshakeable confidence in their own righteousness. Dangerous because it gives them false courage to kill themselves, which automatically removes normal barriers to killing others. Dangerous because it teaches enmity to others labelled only by a difference of inherited tradition. And dangerous because we have all bought into a weird respect, which uniquely protects religion from normal criticism. Let's now stop being so damned respectful!

We've reached a truly remarkable situation: a grotesque mismatch between the American intelligentsia and the American electorate. A philosophical opinion about the nature of the universe which is held by the vast majority of top American scientists, and probably the majority of the intelligentsia generally, is so abhorrent to the American electorate that no candidate for popular election dare affirm it in public. If I'm right, this means that high office in the greatest country in the world is barred to the very people best qualified to hold it: the intelligentsia, unless they are prepared to lie about their beliefs. To put it bluntly American political opportunities are heavily loaded against those who are simultaneously intelligent and honest.

An atheist is just somebody who feels about Yahweh the way any decent Christian feels about Thor or Baal or the golden calf. As has been said before, we are all atheists about most of the gods that humanity has ever believed in. Some of us just go one god further.

The population of the US is nearly 300 million, including many of the best educated, most talented, most resourceful, humane people on earth. By almost any measure of civilised attainment, from Nobel prize-counts on down, the US leads the world by miles. You would think that a country with such resources, and such a field of talent, would be able to elect a leader of the highest quality. Yet, what has happened? At the end of all the primaries and party caucuses, the speeches and the televised debates, after a year or more of non-stop electioneering bustle, who, out of that entire population of 300 million, emerges at the top of the heap? George Bush.

The fact that life evolved out of nearly nothing, some 10 billion years after the universe evolved out of literally nothing, is a fact so staggering that I would be mad to attempt words to do it justice.