A tract for our times

Book review: Edward O Wilson: Consilience: The Unity of Knowledge. Alfred A Knopf: £18.99

E O Wilson has achieved world-wide fame for his writings as a biologist: on ants and termites, on the diversity of life, on instinct and human nature, on biophilia (or innate love of life), and on much else besides. Throughout his work is a strong thread of philosophy, sometimes implicit, sometimes explicit. His latest book draws it out, ties his thinking together knots and all, and leaves a lasting personal testament.

Consilience is an unfamiliar word. It was used by the philosopher of science William Whewell in 1840 to suggest an interlocking of causal explanations across all disciplines, or, in the sub title of Wilson's new book, the unity of knowledge. 'The Consilience of Inductions takes place when an Induction, obtained from one class of facts, coincides with an Induction, obtained from another class'. The question is how to locate this unity of knowledge. Wilson does so in science. On this hangs some lively controversies over the last quarter century.

I was the witness of a dramatic - and infamous - occasion at the meeting of the American Association for the Advancement of Science in 1976. Wilson's massive work Socio-biology: The New Synthesis had just been published. In it he examined the evolutionary origins of the social behaviour of animals, including humans. When he sought to lay out his arguments at a public meeting, he was shouted down by a group of chanting bobbysoxers, showered with water, and accused of Naziism. This ideological onslaught was associated with a fellow Harvard academic Richard Lewontin, who with others later wrote a bill of accusation against Wilson in the New York Review of Books. I am glad to say that Wilson, a man of strong mind but gentle manners, was undeterred. The politics and the ideologies have since changed. Most continuing opposition to his ideas relies to some extent on misrepresentation of them.

If the unity of knowledge can be found in science, what sort of science is it? It is not the vulgar reductionism, or taking apart of things to their component elements, of which he is sometimes accused. Reductionism may be a necessary beginning. But the character and behaviour of the parts are not the same as those of the whole, and in Wilson's words reduction has to be followed by reassembly, reassembly by synthesis, synthesis by predictability, and predictability by consilience, or interlocking with other disciplines.

Until the 18th century, there was a measure of unity of knowledge, or orderly understanding of the universe. Thereafter it became fragmented. The impact of science was devastating to the accepted wisdom of the past. As Wilson writes:

'... pre-scientific people, regardless of their innate genius, could never guess the nature of physical reality beyond the tiny sphere attainable by unaided common sense. Nothing else ever worked, no exercise from myth, revelation, art, trance, or any other conceivable means; and notwithstanding the emotional satisfaction it gives, mysticism, the strongest pre-scientific probe into the unknown, has yielded zero'.

Since then many scientists have slipped all too easily into the boxes of their speciality, shut the lids, and thereby lost their ability to put things together and see the world as a whole. Others working in the humanities, the arts, religion, psychology, sociology and a myriad other disciplines have often shuddered back from science as something alien and hostile. Hence Snow's famous analysis of the two cultures and the widening gap between them.

Wilson's call for consilience between them goes back to what he describes as:

'...deciphering the hereditary orderliness that has borne our species through geological time and stamped it with the residues of deep history'.

There is a biology of human nature, derived from natural selection of the most useful genes, which manifests itself in all human societies: the way we express different wavelengths of light in terms of colour, our mating behaviour, our taboos on incest, our territorial attitudes, our facial expressions (analysed by Darwin in his recently republished book The Expressions of the Emotions in Man and Animals), and our systems of right and wrong.

The interaction of this genetic inheritance with the specific cultures to which we belong is a familiar battle ground. Wilson deals with the nature/nurture debate with elegance and skill. Just as there are genes (or epigenetic "development of an organism under the joint influence of heredity and environment"), so, in Richard Dawkins's phrase, there are memes, or units of information, which comprise the moving elements of human culture. The two are not in conflict. Understanding them is always difficult. But no understanding is possible without grasping the underlying science and the influences which affect the range of choices we make every day.

I have long found curious some of the opposition which Wilson's ideas have aroused. Such opposition often has a pre-Darwinian flavour. His ideas are particularly repellent to postmodernist philosophers. Such people will not welcome Wilson's description of their ideas as:

'sparks from firework explosions that travel in all direction, devoid of following energy, soon to wink out in the dimensionless dark'.

Nor will those who see ethics as God-given from on high welcome Wilson's account of how ethics has developed through the processes of natural selection. In an entertaining whimsy, he works out how termites, endowed with human brains, might create an ethics that met their biological requirements: it would involve respect for darkness, sexual restraint for all but the royal family, consumption of mates' faeces and dead skin, and cannibalism of the sick and injured.

Wilson boldly - and cheerfully - applies his methodology in other fields, including sociology, economics, mythology and the visual arts. It leads him to reclassify Homo sapiens as Homo proteus

'... with indeterminate intellectual potential but biologically constrained ... huge compared to other animals, parvi-hirsute, bipedal, porous, squishy, composed mostly of water. Runs on millions of co-ordinated delicate biochemical reactions... short-lived, emotionally fragile. Dependant in body and mind on other earthbound organisms ... starting to regret deeply the loss of Nature and ... other species".

The last part of the book is a sad account of the insensate damage that humans are doing to their natural environment through their own multiplication, consequent air, water and soil pollution, and destruction of biodiversity. His pleas for corrective action may be familiar, but they lose none of their authority or force.

This is a book to be lastingly remembered. It is written in characteristically lively and eloquent style, with splendid forays into the interstices of science. There are occasional blemishes: unexpected use of jargon and unnecessary obscurities (almost as if down-loaded from something else), which make bits of the text hard going. Sometimes Wilson complicates a robust argument with a false analogy. But most readers will enjoy as well as learn enormously from it.

Does he make his case? I thought that he did, although from time to time I had doubts about how far it could be pushed. It is always a nice question to determine the frontiers between genes and memes. Reviews of the book elsewhere tell an interesting story: good in Nature and Scientific American, cool in one or two of the broadsheets, mixed in the New Scientist and sour in Science magazine. It seemed to me striking how often criticisms were beside the point. For myself I pay the book a high compliment: when I had finished it, the world looked and felt a little different, and I understood many things I had not understood before. It is a tract for our times.