Animals have long functioned as emblems of the virtues and vices. Everyone knows that lions are brave, dogs faithful and rats treacherous. Most of these analogies owe more to human prejudice than to close observation of the species in question; rats do not rat on each other and wolves are far from wolfish. But once fossilised in language, the symbolism is hard to dislodge.
Every new discovery in the field of animal behaviour adds to the stock of meta-phor. At the beginning of the 20th century, a Norwegian boy noticed that certain of his hens always pecked others. He later immortalised his finding in the phrase "the pecking order". The business world is particularly addicted - for reasons that can readily be imagined - to simian metaphors. Young entrepreneurs are "alpha males", CEOs "silverbacks". But the political left also plays this game. Its ape of preference, the bonobo, is egalitarian, matriarchal and rampantly promiscuous. Frans de Waal speculates that when Helena Bonham Carter told reporters she had got in touch with her "inner ape" it was a bonobo she had in mind.
Animal analogies often serve a crude political purpose, namely to enshrine as uniquely "natural" whatever way of life we happen to prefer. They provide us with what the Russian thinker Bakhtin called an "alibi in being". As a result, the entire enterprise of psychological naturalism has come under suspicion. But if pursued with care and subtlety, it can avoid such reproaches. Philosophers from Aristotle through to Mary Midgley have shown that it is possible to treat man as part of the animal kingdom without detracting from his dignity. Culture transforms but does not negate our biological inheritance; we are animals of a very peculiar kind, but animals none the less.
De Waal is in this tradition of sophisticated, non-reductive naturalism. A leading expert on primate behaviour, he argues that morality is not a uniquely human institution - a gift from above, as it were - but rooted in feelings of sympathy common to all the great apes and indeed many other mammals. Apes comfort one another, help the sick and aged, and have even been known to care for members of other species. That such altruistic behaviour probably evolved in response to evolutionary pressures does not make it any less genuinely altruistic. A trait that is "instrumental" on the evolutionary level may none the less be entirely non-instrumental on the level of individual psychology. Kindness is kindness, in apes as well as humans, and not a cunning stratagem on the part of rational maximisers.
However, if human morality has roots in sympathy, it also has roots in the very different principle of group solidarity. Chimpanzees make enormous sacrifices for members of their group, yet can be utterly ruthless in their treatment of aliens. De Waal hypothesises that these two traits are somehow connected. "The profound irony is that our noblest achievement - morality - has evolutionary ties to our basest behaviour - warfare." Hence the frequently observed complicity of socialism with nationalism; solidarity is strongest in communities united in hostility towards an external enemy.
The twin roots of human morality - sympathy and solidarity - are in direct conflict with one another. Sympathy extends naturally to all sentient beings, while solidarity is limited to members of the tribe. Those who preach the ethics of sympathy will always be regarded as traitors and blasphemers by defenders of the ethics of solidarity. De Waal's interesting point is that this well-known conflict takes place not between our spiritual and animal natures, as is usually claimed, but rather within our animal nature. The difference between us and the other apes is simply that we are conscious of it as a conflict and can devote ourselves to its resolution, whereas they are at its mercy. Of course, we are also conscious of the failure of all our attempts at resolution, and hence prey to remorse and self-hatred.
Persuasive as de Waal's analysis is, it concentrates too much on the similarities between us and the great apes, ignoring the vast differences arising from our use of language. These are differences not merely of degree but of kind. For example, because apes cannot send messages to one another over a distance, their communities are unable to grow beyond certain natural limits, whereas human communities, held together as they are by words, are capable of indefinite expansion. The introduc- tion of language also creates rival sources of power, as priests, rhetoricians and philosophers challenge the rule of physical strength. Chimpanzee alpha males have only brute force to fear, whereas their human equivalents must contend with the ridicule of those more knowledgeable and persuasive than themselves. Who ultimately holds the reins is never entirely clear, and many that fancy themselves first are in fact last. Compared with the ambiguities of human politics, the chimp variety is, in the end, a rather dull affair.