Typically, defenders of experiments on animals do not deny that animals suffer. They cannot deny the animals' suffering, because they need to stress the similarities between humans and other animals in order to claim that their experiments may have some relevance for human purposes. The experimenter who forces rats to choose between starvation and electric shock to see if they develop ulcers (which they do) does so because the rat has a nervous system very similar to a human being's, and presumably feels an electric shock in a similar way.
Peter SingerWhatever the reason, for most of the present century, the literature and publicity of the old established [animal welfare] groups made a significant contribution to the prevailing attitude that dogs and cats and wild animals need protection, but other animals do not. Thus people came to think of "animal welfare" as something for kindly ladies who are dotty about cats, and not as a cause founded on basic principles of justice and morality.
Peter SingerWell the real concept of basic needs if you cut it right down are simply the physical needs that are unavoidable for all of us. So to have enough calories to keep our bodies going. Have shelter from extreme elements. To have water that is safe to drink, So I think that's the core of it.
Peter SingerEgoism... is not eliminated by economic reorganization or by material abundance. When basic needs are satisfied, new 'needs' emerge. In our society, people want no simply clothes, but fashionable clothes; not shelter, but a house to display their wealth and taste.
Peter SingerSo far as this argument is concerned nonhuman animals and infants and retarded humans are in the same category; and if we use this argument to justify experiments on nonhuman animals we have to ask ourselves whether we are also prepared to allow experiments on human infants and retarded adults; and if we make a distinction between animals and these humans, on what basis can we do it, other than a bare-faced - and morally indefensible - preference for members of our own species?
Peter Singer