"To hold vivisection to be never justified is a hard belief. But so is its opposite. I believe it is never justified because I can see nothing which lets us pick on animals that would not equally let us pick on idiot humans or, for the matter of that, on a few humans of any sort whom we might sacrifice for the good of the many. If we do permit vivisection, here if anywhere we are under the most stringent minimum obligations. The very least we must make sure of is that no experiment is ever duplicated, or careless, or done for mere teaching's sake or as a substitute for thinking. Knowing how often, in every other sphere, pseudo-work proliferates in order to fill time and jobs, and how often activity substitutes for thought, and then reading the official statistics about vivisection, do you truly believe we do make sure?"

“When factory farmers tell us that animals kept in 'intensive' camps are being kindly spared the inclemency of a winter outdoors, and that calves do not mind being tethered for life on slats because they have never known anything else, an echo should start in our historical consciousness: do you remember how the childlike blackamoors were kindly spared the harsh responsibilities of freedom, how the skivvy didn't feel the hardship of scrubbing all day because she was used to it, how the poor didn't mind their slums because they had never known anything else?”

“To us it seems incredible that the Greek philosophers should have scanned so deep into right and wrong and yet never noticed the immorality of slavery. Perhaps three thousand years from now it will seem equally incredible that we do not notice the immorality of our oppression of animals.”

“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 the obligation to recognise and respect the rights of animals.”

“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.”

“Reason can always disarm the irrational. If reason finds itself to be irrational, it can disarm it; and if one finds reason and discovers that eating animals is immoral, unnecessary, and done largely for superstitious reasons, then one is delivered from the compulsion to do it.”