Chaos theory, a more recent invention, is equally fertile ground for those with a bent for abusing sense. It is unfortunately named, for 'chaos' implies randomness. Chaos in the technical sense is not random at all. It is completely determined, but it depends hugely, in strangely hard-to-predict ways, on tiny differences in initial conditions.

I'm not so fond of the sort of science fiction that isn't really science fiction but is sometimes thought to be - Gothic princesses and white horses and bats and castles and things.

The rule of thumb based into the brain by natural selection would not have been, Be nice to your kin and be nice to potential reciprocators. It would have been, Be nice to everybody, because everybody would have been included.

Nature is not cruel, only pitilessly indifferent. This is one of the hardest lessons for humans to learn. We cannot admit that things might be neither good nor evil, neither cruel nor kind, but simply callous-indifferent to all suffering, lacking all purpose.

Even if not a single fossil has ever been found, the evidence from surviving animals would still overwhelmingly force the conclusion that Darwin was right.

I think we certainly benefit from social institutions which encourage us towards moral behavior. It's very important to have law. It's very important to have a moral education.

As my colleague, the physical chemist Peter Atkins, puts it, we must be equally agnostic about the theory that there is a teapot in orbrit around the planet Pluto. We can't disprove it. But that doesn't mean the theory that there is a teapot is on level terms with the theory that there isn't.