This is the conclusion of the review that began last Sunday.

ON HER DEATHBED Gertrude Stein was asked, "What is the answer?" - to which she replied, sensibly enough, "What is the question?"

Both Edward O. Wilson in On Human Nature and Mary Midgley in Beast and Man pose the same question in their differing but complementary, compellingly interesting and enormously important books. Wilson eloquently states it thus: "These are the central questions that the great philosopher David Hume said are of unspeakable importance: How does the mind work, and beyond that why does it work in such a way and not another, and from these two considerations together, what is man's ultimate nature?"

Some question, as they say. And some answer (assuming that such a question has an answer). For Wilson the answer is biological; we are prisoners of our flesh. Man is not a bird; he cannot fly. Birds can fly. Bats can fly. Machines can fly. But man is rooted on earth, eventually in earth - every man owes nature his death - by his biology which is, in the most profound sense, his destiny. This is undeniable, its ramifications are immeasurably vast and within the terms of Wilson's argument they seem irrefutable: our physical form is indeed genetically determined. So, Wilson says, are the forms of our behavior.

"There are social traits occurring through all cultures which upon close examination are as diagnostic of mankind as are distinguishing characteristics of other animal species," Wilson writes," - as true to the human type, say, as wing tessellation is to a fritillary butterfly or a complicated spring melody to a wood thrush." Yet in man, unlike the butterfly or the wood thrush, the channels of development "are circuitous and variable. Rather than specify a single trait, human genes prescribe the capacity to develop a certain array of traits. In some categories of behavior, the array is limited and the outcome can be altered only by strenuous training - if ever. In others, the array is vast and the outcome easily influenced." Wilson cites C.H. Waddington's developmental metaphor of a ball rolling down a hill. At the top of the hill there is one route but as the ball descends the topography becomes more complex - full of ridges and valleys, twists and turns, highways and byways - but it is nonetheless a topography and it will eventually be mapped as the structure of the brain has been mapped. "The learning potential of each species appears to be fully programmed by the structure of its brain, the sequence of release of its hormones, and, ultimately, its genes," Wilson writes.

Sociobiology is an all-inclusive concept - like Hegel's philosophy, Marx's economics, the Pope's religion, Vico's history, Yeasts's vision, to name a few others - and, as such concepts do, it has a certain grandeur, well-suited to our age of science. We might as well call it genetic determinism and, in fact, Wilson does, with many elaborations and qualifications, including those noted above.

Yet man is also programmed to hope. "Pure knowledge is the ultimate emancipator," he writes. "It equalizes people and sovereign states, erodes the archaic barriers superstition and promises to lift the trajectory of cultural evolution. But I do not believe it can change the ground rules of human behavior or alter the main course of history's predictable trajectory. Self-knowledge will reveal the elements of biological human nature from which modern social life proliferated in all its strange forms. It will help to distinguish safe from dangerous future courses of action with greater precision. We can hope to decide more judiciously which of the elements of human nature to cultivate and which to subvert, which to take open pleasure with and which to handle with care. We will not, however, eliminate the hard biological substructure until such time, many years from now, when our descendants may learn to change the genes themselves."

So, in a sense, man is stuck in his biological mud but perhaps determined - in two senses - to be free. That is Wilson's answer to Hume's "unspeakably important" question. He buttresses his argument with illuminating and truly fascinating comparisons to other cultures and other social species while he focuses on four of the elemental categories of human social behavior - aggression, sex, altruism and religion - scrutinizing them rigorously, examining them scientifically. For sociobiology claims to be a new science. That is, it deals with facts, with verifiable data, some known, some not yet known, which when all the data are in, and correctly analyzed and interpreted, will purport to explain everything, given world enough and time: war and suffering, the Appassionata and the Pieta; Auschwitz and Aeschylus and Mother Theresa; the past and the future; and you and I and the love we felt at breakfast, the argument we had at noon. Hence laughter, too, and the whole gamut of human thoughts and feelings and deeds. But sociobiology depends also on a mythology, a unifying structure of belief whose validity is in direct proportion to its correspondence with perceived reality. So last week we left man sitting in his biological swamp, working hard on an evolutionary epic for the new myth, and Wilson out on his hubristic limb, an exciting position but a dangerous one.

"What counts as a fact depends on the concepts you use, on the questions you ask," Mary Midgley writes in Beast and Man . She illustrates her point with a simple but apt analogy, for which she has a brilliant facility. "If someone buys stamps, what is going on can be described as 'buying stamps,' or as the pushing of a coin across a board and the receiving of paper in return - or as a set of muscular contractions - or one of stimulus-response reactions - or a social interaction involving role-playing - or a piece of dynamics, the mere movement of physical masses - or an economic exchange - or a piece of prudence typical of the buyer. None of these is the description. There is no neutral terminology. So there are really no wholly neutral facts. All describing is classifying according to some conceptual scheme or other."

While Midgley covers much of the same ground as Wilson, she differs in her conceptual scheme, which makes it especially rewarding to read the two books one after the other, beginning with On Human Nature . Wilson is a biologist first and a philosopher second; Midgley is a philosopher vastly read in psychology, anthropology and ethology. (She is Senior Lecturer in Philosophy at the University of Newcastle-upon-Tyne, England, and if I were anywhere near I'd take her course. Of course, if I were near Cambridge I'd take Wilson's, too.) She began the studies that led to Beast and Man by thinking about human nature and the problem of evil. The result is a modest, wise, beautifully written and learned book, as simple as possible - she detests jargon of all kinds - and stunningly intelligent.

"The evils in this world . . . are real," she writes. "That they are so is neither a fancy imposed on us by our culture, nor one created by our will and imposed on the world. Such suggestions are bad faith. What we shall abominate is not optional. Culture certainly varies the details, but then we can criticize our culture. What standard do we use for this? What is the underlying structure of human nature which culture is designed to complete and express?" To examine that underlying structure, Midgley looks at the differences and the similarities between man and other species. Understanding is relating, and context is all important.

Consider the case of Paul, who buys a house with an acre of land "though he can scarcely afford it . . . The 'facts' of the particular transaction are not enough to classify it, or explain it, even economically, unless they include motives. (Motives, of course, are not just his private states of mind, but patterns in his life, many of which are directly observable to other people.) We cannot say what he is doing until we know why he does it." This is not a simple case. Paul wanted privacy; he has a horror of being stared at. In most social creatures, the direct stare is an open threat. "It may well have something to do with the fact that predators naturally stare fixedly at prospective prey before jumping on it," Midgley writes. "And they are of course regarding it as an object, not as a possible friend - which is just the effect a direct stare conveys to a human being." As stated here, Midgley's argument is stripped of illustration, greatly condensed and simplified, but it is nonetheless possible to understand Paul's motive in buying the land he could not afford: it was what he said it was - the desire for privacy - although he almost certainly didn't understand its primitive biological roots.

Midgley takes motives very seriously. Man can understand neither his nature nor his behavior until he understands his motives. "It usually concerns us very little to know the exact details of a man's outward actions," she says. "But it can concern us vitally to know his intentions. We see his action; he has left the house. But is he angry? Is he considering leaving for good?Did he misunderstand what we said? Would he inform on us?Or has he just gone shopping? These are all the kinds of questions which have shaped our language. All the terms in which we speak of human behavior have this bias, including, indeed, behavior itself . . . There would certainly be trouble if we are forced to choose between describing outer actions and inner experience - if we could not have both. But we can have both. People have insides as well as outsides; they are subjects as well as objects. And the two aspects operate together. We need views on both to make sense of either. And, normally, both are included in all descriptions of behavior."

Wilson, she points out, scrupulously avoids any discussion of motive in Sociobiology , but not mentioning it doesn't make it go away. He does discuss it, at least by implication, in On Human Nature , but not very adequately. Mother Theresa ministers to the desperately poor of Calcutta because "she is secure in the service of Christ and the knowledge of her Church's immortality." She wants to get to heaven, in other words, and that is undoubtedly so. Nonetheless, it seems an extremely simplistic motive for such complex and selfless behavior. A lot of people want to get to heaven, after all, and some of them, as in Ireland, are shooting their brothers. Midgley's explanation is equally simple but much more plausible: "To give meaning to life, we want to see what we do as an element in something that, as a whole, satisfies us."

The behavior of Mother Theresa, Paul, and the man who left the house is purposive. Other actions are expressive: crying, laughing, snarling, smiling, slouching, and so on. To understand what such noises and expressions mean, "there is no substitute for grasping the kind of subjective, conscious states in which such noises are typically made, and for this you need to be capable of something like it yourself." Midgley says. Thus we assume the existence of a "human nature" instead of a blank. I think, therefore I am, as Descartes reasoned; you speak, therefore you are. More particularly, you smile, therefore you are pleased (because I smile when I am pleased); you weep, so you are sad; and so on. Such feelings cannot be divorced from thoughts. In fact, "it is wrong to say that we just establish the facts, and then, quite separately, take up an attitude to them, view them as good or bad. Thought and feeling must go together throughout."

The intellect divides the indivisible - mind from body, thought from feeling, form from content, natural from supernatural - but such dichotomies do not exist in nature. Nature, including man, is a unity. "The whole range of human possibilities is so much wider than any one of us can encompass that people of the most diverse sorts are needed to cover it," Midgley writes. "The full human sound goes up only from the whole orchestra." (Culture helps simplify this rich confusion by providing separate roles for people of obviously different types.) E pluribus unum , as this nation's motto puts it. So we live in what Midgley describes as a rough but tolerable equilibrium among contending forces, deploring what we sometimes glory in. Ambivalence is part of our nature, our inhibitions weak but genuine - else we would not have developed a morality.

The nature of any one of us - let alone the nature of man - is much more complex than any one of us can fathom, which of course cannot stop us from telling stories, making myths and asking questions about it. We can always do with new stories, new questions. "Asking different kinds of questions produces quite different kinds of answers," Midgley writes; "they are usually not reducible to one another, though they must be compatible. Slicing the world in different directions reveals different patterns. Jelly rolls, sliced downward, have a spiral structure. Sliced across, they have stripes. Stripes are not reducible to spirals, nor vice versa, and will not become so by further analysis. Both are real, and the two patterns can be related if we understand the relation between the two slicing angles."

So there it is. How you see it depends on how you slice it. All you have to remember is that there's more than one way to cut it. Let those who wish to ponder these questions further go to the books under review. They are the most stimulating, the most provocative and the most illuminating works of nonfiction I have read in some time.