It is raining DNA outside. On the bank of the Oxford canal at the bottom of my garden is a large willow tree, and it is pumping downy seeds into the air. ... spreading DNA whose coded characters spell out specific instructions for building willow trees that will shed a new generation of downy seeds. ... It is raining instructions out there; it's raining programs; it's raining tree-growing, fluff-spreading, algorithms. That is not a metaphor, it is the plain truth. It couldn't be any plainer if it were raining floppy discs.

The atheist view is correspondingly life-affirming and life-enhancing, while at the same time never being tainted with self-delusion, wishful thinking, or the whingeing self-pity of those who feel that life owes them something.

I am not advocating a morality based on evolution.

I am very hostile to religion because it is enormously dominant, especially in American life. And I don't buy the argument that, well, it's harmless. I think it is harmful, partly because I care passionately about what's true.

On one planet [earth], and possibly only one planet in the entire universe, molecules that would normally make nothing more complicated than a chunk of rock, gather themselves together into chunks of rock-sized matter of such staggering complexity that they are capable of running, jumping, swimming, flying, seeing, hearing, capturing and eating other such animated chunks of complexity; capable in some cases of thinking and feeling, and falling in love with yet other chunks of complex matter.

But what, after all, is faith? It is a state of mind that leads people to believe something - it doesn't matter what - in the total absence of supporting evidence. If there were good supporting evidence then faith would be superfluous, for the evidence would compel us to believe it anyway. It is this that makes the often-parroted claim that 'evolution itself is a matter of faith' so silly. People believe in evolution not because they arbitrarily want to believe it but because of overwhelming, publicly available evidence.

We are survival machines – robot vehicles blindly programmed to preserve the selfish molecules known as genes. This is a truth which still fills me with astonishment.