At a conference of sociologists in America in 1977, love was defined as "the cognitive-affective state characterized by intrusive and obsessive fantasizing concerning reciprocity of amorant feelings by the object of the amorance." That is jargon - the practice of never calling a spade a spade when you might instead call it a manual earth-restructuring implement - and it is one of the great curses of modern English.

To my mind, the only possible pet is a cow. Cows love you. They will listen to your problems and never ask a thing in return. They will be your friends forever. And when you get tired of them, you can kill and eat them. Perfect.

There is more difference between a zebra and a horse, or between a dolphin and a porpoise, than there is between you and the furry creatures your distant ancestors left behind when they set out to take over the world.

I can't fix the world. If you want to make a difference in life, you have to direct your energies in a focused way.

I often feel I'm a disappointment to people because they expect me to be the guy in the books. When I sit next to someone at a dinner party I can see they expect me to be quick and witty, and I'm not at all.

There is the odd exception, like Albert Einstein, but as a breed, scientists tend not be very good at presenting themselves.

Most of what has lived on Earth has left behind no record at all.