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. The Rights of Animals (1965)
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. The Rights of Animals (1965)
When factory farmers tell us that animals kept in 'intensive' (i.e. concentration) 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? The Rights of Animals (1965)