BOOK REVIEW / Plan for the Apes: A new study argues that apes, our near evolutionary relations, should

SINCE the end of the 17th century, when the first chimpanzee was shipped from Africa, apes have served to define the limits of the human in European thought. They are the measure of the distance we keep from the rest of nature. The appearance of these formerly mythical creatures was the occasion for intense speculation by Enlightenment thinkers - as if a yeti, say, or a Sasquatch man, or Australopithecus, were to turn up alive today.

The Scottish anthropologist Lord Monboddo, writing in the late 18th century, considered the orang-utan (as the chimpanzee was misleadingly referred to) to be proto-human - an example of man in the state of nature, as he had been before the acquisition of language. Rousseau took up this idea enthusiastically, but most of his contemporaries believed that apes were, if anything, degenerate versions of mankind, beyond the pale of the human. 'Other people have strange notions, but they conceal them,' wrote Dr Johnson of Monboddo, while Thomas Love Peacock mocked him in Melincourt, a satirical novel in which a mysterious, bearded arriviste, Sir Oran Haut-ton, becomes a member of Parliament and eventually prime minister, his taciturn manner being taken as the sign of exemplary gravity and discernment.

Yet Monboddo's inkling of hominid evolution turned out to be broadly correct. He was also right to think that it is not necessary to speak to be human. Infants cannot speak, nor can some mentally impaired people, yet no one doubts they are of our kind. And Monboddo was right, to an extent, in thinking that apes were capable of mastering language. When, in the present century, primate researchers finally managed to teach apes to talk, it was in sign language, the language of the deaf. But no one doubts the deaf are human either.

In the first half of the 18th century the fluid speculation of Enlightenment thought congealed into an elaborate hierarchy of race and species, a vision of a fixed order of nature, divinely ordained, that sustained European imperial expansion. Then in 1859 the publication of The Origin of Species unveiled Darwin's revolutionary theory of the relation between living things, a relation that implied common ancestry for men and apes - or rather, for men and other apes. Darwinism marks the victory of scientific taxonomy: at the same time as it stresses the historical continuity between species, it fixes the genetic distance between the other apes and us.

But not the ethical distance. We are still in the process of coming to terms with the moral implications of Darwin's revelation. The Great Ape Project is the most recent result of this: a proposal by a group of biologists, anthropologists, psychologists and philosophers that the other great apes be 'included in the community of equals' - that human rights should be extended to the gorilla, the orang-utan and the two species of chimpanzee; that these creatures, like human beings, should not be killed, nor be subject to the deliberate infliction of pain, nor to arbitrary detention - and that great apes in captivity in zoos and laboratories should therefore be returned to forest reserves and 'independent territories' established for them in their original habitat.

It is a startling proposal, going beyond the demands even of many animal liberationists (though its sponsors include two of the founding fathers of the animal liberation movement). Putting it into effect would involve giving apes the same legal rights as children and mentally impaired adults. In legal terms, instead of being property, as other animals (at least potentially) are, apes would be persons. Since they could not represent themselves - no non-human apes have yet been taught to read - we, humans, would be their guardians.

The authors argue, variously, that the extension of such rights to some non-human primates is a logical continuation of the historical widening of moral concern to include other races, the same concern that abolished slavery and established the universal declaration of human rights. They argue that primate research over the last few decades shows there is no significant criterion of personhood that apes cannot fulfil, and that the moral boundary we draw between us and them is indefensible.

Objections to such a proposal come from several directions. What would the obligations, as opposed to the rights, of a non-human person be? Would they be enjoined not to kill or torture each other - or other animals - or us? As a result of the observations of human primatologists we know that chimps, for instance, are capable of systematic violence towards their own kind. This may well reinforce the view that they are rather like us, but how would the reconstituted sylvan communities of great apes that are envisaged in the current proposal be policed to prevent murder, or simicide? There is a touch of Brave New World about it.

Another important question is: why stop at apes? Once you jump the species barrier why not include all primates, or all mammals, or all animals with central nervous systems? Our tenderness towards specific animals tends to begin as they become rare. The number of great apes is small, thanks largely to human depredation, so the practical difficulties of implementing their new status would not be insurmountable. But some of the contributors to the book see the ape project as the first stage of an extension of rights to a much greater range of sentient beings. Such an extension would strain not just the moral imagination but the purse strings of the world. This may be why the authors of the book have - rather arbitrarily - excluded the two other remaining apes, gibbons and siamangs, species which are, as yet, more numerous than the big three.

In which case, an objector might say, why not stop at the obvious point, the point we have already reached if we subscribe to Western liberal doctrine, where the limits of the species are also the limits of reciprocal moral expectation? We can, after all, be kind to animals without needing to believe that they are of our kind. We can hold dissenting opinions - about laboratory experimentation, or factory farming, or eating meat - while maintaining that human beings are significantly different. Indeed, it may be because we maintain the importance of this difference that we consider that we, as Homo sapiens, have special obligations to our fellow animals. Sagesse oblige.

The counter-argument is that, in the case of apes particularly, the point at which to stop is not obvious. The difference between us and other apes is genetically tiny and very recent in evolutionary time. It's only a few thousand generations back that the Ur-man merges with the Ur-chimp (if you accept the current account of hominid evolution). Two hundred thousand generations and all apes are one. Some non-human apes can hybridise with each other, as lions can with tigers, though it doesn't happen very often in either case. And it's not entirely impossible that a human could produce offspring with another species of ape. (It sounds like something out of the National Enquirer, but only a decade ago an American businessman was widely reviled for trying to arrange something of the sort between a gorilla and a Japanese prostitute. And in the dawning epoch of genetic manipulation and surrogate parenthood, such an event may come to seem less appalling than it does today.) Nor is it totally out of the question that a relict of some intermediate species, Australopithecus, say, could still turn up. Were that to happen, Richard Dawkins argues here, the existing basis of common values would be threatened, and racism would blur with speciesism.

This is perilous ground, where the extension of concern into the non-human realm begins to threaten the liberal consensus on the uniformity of human nature. Stephen Clark, taking up Dawkins's point, argues that the fragile taxonomic unity of the human species will not bear much weight when it comes to asserting a moral difference between us and our fellow apes. He proposes, instead, a greater humankind corresponding to the superfamily Hominoidea, which includes them and our proto-hominoid ancestors.

The contributors to The Great Ape Project write from a Western, Darwinist perspective. None of them comes from places where great apes come from, and there is only the most fleeting consideration of non-European strains of thought. In Buddhism, for instance, the notion of reincarnation puts humans in a metaphysical relation to other animals quite different from that posited by Western evolutionary orthodoxy. It is not necessary to believe in reincarnation to see that it is a very powerful metaphor for the interdependence of living things. And it seems particularly inappropriate that a challenge to anthropocentricity, a proposal for the extension of personhood to beings other than ourselves, should allow itself to be vulnerable to a charge of ethnocentricity. It adds to the slightly fantastical air of the whole project. It will inevitably take time before the message presented here reaches the inhabitants of Zaire and Sumatra; let it not be unnecessarily hindered in its passage from the West.

But there is no doubt that this is an important book. It dramatically extends the debate about animal rights, making it central to ethics. Apes once again become, as in the Enlightenment, the subject of radical moral speculation. Such speculation contributes to the urgent debate about the pathological increase in human population and our corresponding abuse of natural resources, issues that affect our well-being and that of our fellow apes alike. Respect for the great apes is symbolically valuable: it involves recognition not just of our common ancestry but of the principle of continuity that links us to all other living beings, the neglect of which has put us all in peril.

'The Great Ape Project', edited by Paola Cavalieri and Peter Singer, is published by 4th Estate at pounds 9.99

(Photograph omitted)