Those who experiment with operations or the use of drugs upon animals, — Animal testing

"Animals can not disapprove, but they can complain and protest, at least until their vocal chords are cut to spare experimenters their protests."

"Last year a Dutch animal breeding centre sent me two chimpanzees as a gift. I killed one and cut its heart out. The other wept bitterly and was inconsolable. The sad chimp has long since happily mated again and lives with lots of other animals on a pleasant game farm near Villiersdorp. I vowed never again to experiment with such sensitive creatures, but the memory of that weeping chimp has remained with me. It was taken for granted, of course, that he was weeping for his mate but Ive since had some thoughts on the subject which made me wonder whether perhaps he was weeping for the human race. The idea is not as silly as it sounds. In our doings there is much to weep over and even a chimpanzee would never behave in some of the contradictory ways we think of as normal."

"The love of a dog for his master is notorious; in the agony of death he has been known to caress his master, and every one has heard of the dog suffering under vivisection, who licked the hand of the operator; this man, unless he had a heart of stone, must have felt remorse to the last hour of his life."

"One type of medical research involves ascertaining whether certain pathological conditions in humans can be alleviated or cured by certain drugs. Animals are used as "models" upon which to test these treatments. To do this it is necessary for the animal subject to have the condition in question, and in order to bring this about healthy animals are made sick. … It turns out, however, that the conditions artificially induced have little in common with the naturally occurring diseases in animals (when these exist) and much less in common with the diseases in man."

"I dislike the whole business of experiments on animals, unless theres some very good and altogether exceptional reason in a particular case. The thing that gets me is that its not possible for the animals to understand why theyre being called upon to suffer. They dont suffer for their own good or benefit at all, and I often wonder how far its for anyones. Theyre given no choice, and theres no central authority responsible for deciding whether whats done in this case or that is morally justifiable. These experimental animals are just sentient objects; theyre useful because theyre able to react; sometimes precisely because theyre able to feel fear and pain. And theyre used as if they were electric light bulbs or boots. What it comes to is that whereas there used to be human and animal slaves, now there are just animal slaves. They have no legal rights, and no choice in the matter."

"There will come a time when the world will look back to modern vivisection in the name of science as they now do to burning at the stake in the name of religion."