The popular distinction between 'constructive' and 'destructive' criticism is a sentimentality: the mind too weak to perceive in what respects the bad fails is not strong enough to appreciate in what the good succeeds. To be without discrimination is to be unable to praise. The critic who lets you know that he always looks for something to like in works he discusses is not telling you anything about the works or about art; he is saying 'see what a nice person I am.

To my mind, the two most fascinating subjects in the universe are sex and the eighteenth century.

Whenever people say, 'We mustn't be sentimental,' you can take it they are about to do something cruel. And if they add, 'We must be realistic,' they mean they are going to make money out of it.

The fact that there are bigger injustices and wrongs doesn't make it right to sacrifice an innocent monkey. It doesn't alter the case at all.

The person who kills for fun is announcing that, could he get away with it, he'd kill you for fun. Your...life may be of no consequence to anyone else but is invaluable to you because it's the only one you've got. Exactly the same is true of each individual deer, hare, rabbit, fox, fish, pheasant and butterfly. Humans should enjoy their own lives, not taking others'.

I don't hold animals superior or even equal to humans. The whole case for behaving decently to animals rests on the fact that we are the superior species. We are the species uniquely capable of imagination, rationality, and moral choice - and that is precisely why we are under an obligation to recognize and respect the rights of animals.

A medical profession founded on callousness to the pain of the other animals may eventually destroy its own sensibility to the pain of humans.