4th April 1999
I am told that you do not favour the idea of granting rights to great apes. The case for doing so seems to me so clear-cut that I am curious to learn why someone like you, who generally opposes the exploitation of the weak by the strong, is against it. Supporters of the Great Ape Project (GAP) are pressing the New Zealand parliament to extend three basic rights to our nearest relatives, the great apes: the right to life; the right to liberty; and the right not to be tortured.
Why am I prepared to restrict my campaign to the great apes? After all, the central thesis of my book, Animal Liberation, is that the principle which entitles us to regard all human beings as equal-the principle of equal consideration of interests-ought to be applied to all beings with interests. Because all beings capable of experiencing pleasure and pain have interests, this includes all mammals-indeed, all vertebrates, and many invertebrates too. I have not changed my views about extending this principle to all sentient beings, but I am attracted by the chance to extend basic rights beyond our own species right now. The great apes (chimpanzees, gorillas and orang-utans) are not only our closest relatives; they are also, more importantly, beings who possess many of the characteristics which we consider distinctive in our own species. They form close and lasting attachments to others; they show grief; they play; when taught sign language, they tell lies; they plan for the future; they form political coalitions; they reciprocate favours, and they become angry when someone for whom they have done a favour does not respond similarly. Their intellectual abilities have been compared with those of children between two and three years old, and their social bonds are stronger than we would expect from a child of that age. Why should we not recognise the basic rights of such beings, on the same basis as we include all members of our own species, irrespective of age or intellectual ability?
Such a step is not yet possible for all sentient beings. All over the world people are involved in raising and killing animals for food. The extension of rights to all sentient beings will remain politically impossible for a long time, no matter how strong the ethical arguments. By comparison, the step advocated by the GAP would not involve…