It is not uncommon for people approaching the outer shores of middle age to go slightly dotty. Lawyers and accountants who have led exemplary lives marry trophy wives and buy houses in Aspen. With scientists, the syndrome takes another form. Since most of their best work is done when they are young, older scientists, and often the most distinguished ones, sometimes come to feel that the world has already forgotten them. In his later years Einstein was a bit in this position, although he simply did not care, continuing to work on his unified field theory—his Theory of Everything—in complete tranquility. This kind of serene indifference, however, is rare. More often, scientists try to make another grab for the limelight before night descends.

Of many examples known to me, I will mention only two. Julian Schwinger, who died in 1994, was one of the greatest theoretical physicists of this century. Among other things, he developed quantum electrodynamics, the most accurate scientific theory ever devised—an accomplishment for which he shared the Nobel Prize in physics with Richard Feynman and Tomonaga Shin’ichiro in 1965. He was also my teacher (both undergraduate and graduate) at Harvard, and there was no scientist for whom I had greater respect. I was, therefore, appalled when, a few years before his death, Schwinger became an enthusiast for cold fusion. There was, and is, not a shred of evidence that this idea has any scientific merit, but it attracted an odd group of eccentrics and hustlers who welcomed Schwinger like a god descended from Mount Olympus—a hero. What is worse, I have no reason to think that Schwinger was insincere in his enthusiasm.

My second example is the biologist George Wald, who died last year. Born in 1906, Wald was educated at New York University and Columbia. In 1932, he won a fellowship to Berlin and there, in the laboratory of Otto Warburg, he became the first to identify vitamin A in the retina of the eye. This work led to the Nobel Prize in medicine, which he shared in 1967. Wald served for most of his career on the faculty of Harvard.

During the period of the Vietnam war, photographs began to appear of Wald dressed in a turtleneck shirt and wearing what looked like a ponytail as he addressed crowds of adoring youths on matters spiritual and holistic. One evening I happened to be present for one of these lectures at the home of Ruth Nanda Anshen, a woman in New York who published books by well-known scientists on general themes and who gave soirees in her large mansion off Fifth Avenue.

To this day I can see Wald, dressed in a black turtleneck and bent under a lamp as he read, gurulike, from a manuscript, his ponytail glistening in the light. Although I recall little of what he said, I do remember his making some observations about the proton that persuaded me he had less understanding of this subject than a typical undergraduate physics major. While he was droning on, I took the opportunity to study the reactions of I.I. Rabi, also in attendance that evening. Rabi, a professor at Columbia, was one of the most distinguished experimental physicists of this century, a trusted adviser to Presidents, and a great man who had zero tolerance for fools. Having spent over a year interviewing him for a New Yorker profile, I well knew the dangers of asking him a dumb question.

During much of Wald’s talk, Rabi’s eyes were closed, though a seraphic smile occasionally played across his face—a disturbing sign. When the lecture, or perhaps I should say performance, was over, Wald made the mistake of asking for questions. The first hand up was Rabi’s. He was acknowledged with some flourish, and said: “There is something I have always been curious about. Why did homo sapiens have his origin in Africa and not in Canada or South America?” Wald, looking totally bewildered, rose to the bait: “That was not the subject of my lecture.” “I know,” dead-panned Rabi, “but I thought it might be somewhat closer to your area of expertise.” The “somewhat” was especially good. His seraphic smile intact, Rabi then got up and left, with Wald looking as though the air had just been let out of his tires.

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So much for background. Imagine my sinking feeling, then, upon seeing the title of Edward O. Wilson’s latest book, Consilience: The Unity of Knowledge¹ For starters, I could not even find “consilience” in The New American Webster Handy College Dictionary—the only one I happened to have around. (It means something like “jumping together,” and seems to have been invented in 1840 by a man named William Whewell, who used it in a book with the title The Philosophy of the Inductive Sciences.) Just what we need, I thought, a title that is not in the dictionary. And then there was the subtitle: “The Unity of Knowledge.” “Oh, Wilson,” I expostulated, “you have now gone the way of all Walds.”

Well, the news is not quite that bad. Although this book is indeed his Theory of Everything, Wilson, unlike Wald, has not lost his original scientific base. That, at least, is something.

Edward O. Wilson was born in Birmingham, Alabama, in 1929 and raised as a Southern Baptist. “More pious than the average teenager,” he writes here, “I read the Bible cover to cover, twice.” Loving nature, he also spent hours out of doors studying “ants, frogs, and snakes.” His goal was to classify—to identify and give names to—the creatures he came across. But in the fall of 1947, when he entered his sophomore year at the University of Alabama, he met a young assistant professor named Ralph Chermock who told him that if he really wanted to become a biologist, as opposed to some sort of “naturalist” stamp collector, he had to learn about the Darwinian synthesis and modern genetics.

This experience transformed Wilson’s life, and in reading about it I was reminded of something Rabi had once told me. He himself had come from the sort of Orthodox Jewish home where the Hebrew Bible was considered to contain all the cosmology anyone needed to know. But then he discovered in the Brooklyn public library an elementary book on the Copernican system, and he was never again able to regard his family’s beliefs about the universe in the same light. “That was the church I failed,” he said to me—a sentiment I am sure Wilson would understand very well.

Wilson’s most famous work in science, which he began at Harvard in 1950, has to do with the social behavior of insects. His two books, The Insect Societies and The Ant, for which he won a Pulitzer Prize in 1990, are classics. It is a commonplace that ants and other social insects behave in their colonies less like individuals than like the components of a unified brain. Now, the human brain consists of some 100 billion nerve cells, each of them connected to other nerve cells by hundreds, or thousands, of membranes—“wires”—along which electric currents pass. If we could make sense of these connections, they would tell us how the brain works in detail. But, assuming that individual ants in a colony are like cells in a brain, what is it that connects them?

That is the question Wilson sought to answer. It was a puzzle because ant colonies often operate at night, when the ants cannot see each other; and while they do communicate audibly, they do so only on special occasions. Wilson conjectured that the signals connecting them were chemical. Dissecting red harvester ants, he discovered tiny glands emitting what are now known as pheromones. With the aid of a young chemist named Fred Regnier, he then identified the active chemicals, and with the aid of a mathematician named William Bossert, he was able to construct a model of how the signals disperse in time. It was clear that ants do not go to school to learn to respond to these signals. They are born with this ability; it is part of their programming, an example of behavior determined by genes and ultimately by genetic molecules—that is, by physics and chemistry.

So far, so good. But after making these discoveries, Wilson and a few like-minded scientists, notably including the British biomathematician William Hamilton, began to extend the idea of genetically-determined behavior beyond the lower orders of insects, and in particular to develop a theory of the genetic origins of human behavior. This theory is often called “sociobiology,” a term that Wilson may well have invented.

The idea that important elements of our behavior as individuals and in society might be “hard-wired” in our genes by physics and chemistry—and therefore basically not subject to improvement—drove some of Wilson’s colleagues slightly berserk. The effect, one might say, was like dropping a pheromone into an ant colony. Staggering was the number of trees chopped down for the multipage diatribes against Wilson that appeared in places like the New York Review of Books by people like Richard Lewontin and Stephen J. Gould. No slouch when it comes to polemics, Wilson replied in kind—more trees. He also wrote books, including Sociobiology: The New Synthesis (1975), in which he defended and amplified his views.

To someone like me who has no professional stake in this controversy, it seems clear that sociobiology is part of the truth. The question is how much. The fact, to take an example, that there is an incest taboo in every human society, and that it develops automatically in children who have been raised together for the first 30 months of their lives (as Edward A. Westermarck first pointed out at the end of the last century) is clearly traceable to genetics. How this taboo is expressed, however, is societal, and varies from one society to another.

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But that brings me to Consilience. The first half of this book is a very lucid tour of the “hard” sciences—physics, chemistry, and the like. (The list of people Wilson credits with helping him to expound the nonbiological sciences is most impressive.) What all these disciplines have in common is that they are reductionist: underlying the bewildering array of data is a set of units obeying laws that often display a remarkable mathematical elegance. In physics, the reduction goes down to the quark, which is the modern physicist’s atom. In evolutionary biology, it goes down to the gene and its component molecules.

To be sure, as compared with biologists, physicists have it easy. If, for example, we want to study a particular electron, its own “biography” is irrelevant: we can assume that the electron running through the wires of our toaster is identical to an electron in the most distant galaxies. This is the basis of astrophysics and cosmology—and it works. In evolution, by contrast, biography is everything, a fact that makes for enormous difficulty. To understand, step by step, how some grouping of eukaryotic cells evolved into the person named E.O. Wilson, we would need a complete record of the “chance and necessity”—wonderful phrase—that caused one particular assembly of cells to survive when others died out, in a process repeated again and again over the whole course of human evolution. To put the distinction another way, starting from an array of electrons in the wires of a toaster I can guarantee the conditions under which my toast will be burned; starting from the eukaryotic cells, I have no way of predicting the emergence of E.O. Wilson.

Nevertheless, and all these difficulties notwithstanding, studying the underlying biological molecules can indeed lead to an understanding of the basic mechanisms of evolution. For someone like Wilson, the temptation must be irresistible to apply the lessons thereby learned to, essentially, everything. Hence the second half of this book, which constitutes Wilson’s Theory of Everything. He genuinely feels that once we know enough about physics, chemistry, and biology, there will be nothing on earth we cannot explain. And by nothing, he means nothing. Thanks to the principle of “consilience,” he writes in a typical statement, “even the greatest works of art might be understood fundamentally with knowledge of the biologically evolved epigenetic rules that guided them.”

This sweeping assertion is put forward by Wilson in calm, measured tones. Indeed, virtually all of Consilience is written in a voice of statesman-like moderation. None of the opponents of sociobiology is mentioned by name, and the only polemics are reserved for people like Freud, who, so far as I know, is no longer in a position to write to the New York Review of Books. But Wilson’s treatment of Freud does offer an insight into his method in this book, and its flaws.

In several pages devoted to the subject of dreams, Wilson begins by describing Freud’s theories, which he then states are “mostly wrong.” When I read this, I had the same sense of a rug being pulled out from under me as when I read some years ago that eating large quantities of raw carrots could cause cancer. (It turned out that the quantities involved came in freight cars.) Why was Freud “mostly wrong”? Because, according to Wilson, he did not understand the biological basis of dreaming—for example, the rise of acetylcholine in the brain during the dream state.

This sounds like a serious indictment until one asks oneself what it has to do with the content of dreams, which is, after all, what Freud was interested in. That the same thought seems to have occurred to Wilson is confirmed a few pages later when he remarks: “The findings from neurobiology and experimental psychology nevertheless say nothing about the content of the dreams.” He then goes on to make the quite modest claim that he should have made in the first place—namely, that neurobiology, rather than invalidating Freud, can perhaps help to make Freud’s theories “more concrete and verifiable.”

A few years ago, you could buy a wonderful doll that looked like Freud. From its back there dangled a string. The temptation to pull it was overwhelming. When one did so, a recorded voice, in what passed for an Austrian accent, asked, “Vy did you pull my shtring?” Again and again in this book, I felt Wilson pulling my string.

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At one point in Consilience, Wilson constructs a dialogue between two individuals, a “transcendentalist” and an “empiricist.” The transcendentalist holds that some tangible phenomena—perhaps even life itself—require a nonscientific explanation if they can be explained at all. By contrast, the empiricist, who has the proper consilience world view (and who gets most of the good lines in the dialogue), maintains that “all tangible phenomena from the birth of stars to the workings of social institutions are based on material processes that are ultimately reducible, however long and tortuous, to the laws of physics.”

How can one adjudicate between these two positions? Clearly, the transcendentalist argument is not susceptible of proof. To say that, for some phenomena, no scientific explanation is possible requires a leap of faith. But the same holds, if in the opposite direction, for Wilson’s own “empiricist” position. He, too, can offer no proof that it is true; it, too, requires a leap of faith.

So let me propose a third possibility: for all practical purposes, the “long and tortuous” reductions to the laws of physics of which Wilson speaks are so long and tortuous as to render both views—the transcendentalist and the empiricist—indistinguishable. I can illustrate what I mean from the game of chess.

Chess is a determinate enterprise. If one follows the rules, there are, at any given point, a finite number of moves and a finite number of responses to those moves. This means that anyone in a position to consider in advance every move and every riposte could play a perfect game each and every time. Why then is chess interesting? Why are all games not perfect? Why, practically speaking, is chess an indeterminate game?

The answer lies in the numbers. There are 20 possible opening moves by white, and 20 possible responses by black. But thereafter the numbers immediately start to increase. The engineer Claude Shannon, one of the creators of information theory, made the following analysis in the late 1940’s. The average position involves about 30 moves and 30 ripostes; thus, at any given stage, the next move involves some 900 choices. Since in an average game there are about 40 moves, if one ran the whole chain from beginning to end, the number of choices one would have to examine would amount to 900 raised to the 40th power—or about 10 raised to the 118th power. To get some perspective on this absurdly large number—10 followed by 118 zeroes!—bear in mind that the age of the universe in seconds, according to cosmologists, is about 10 raised “only” to the 17th power.

The most powerful chess machine yet built—Deep Blue—can analyze about 200 million positions a second. Thus, to run the entire chain of an average chess game would take Deep Blue, in seconds, about 10 raised to the 110th power. If, in other words, Deep Blue had been running at top speed since the instant of the Big Bang, it would still not have made a dent in analyzing the average chess game. And this is only chess!

Wilson himself chooses to comment on chess machines, and he does so in a very revealing manner. Speaking about the limitations of artificial intelligence, he observes that chess machines work by “brute force.” Although he does not expand on this remark, he must mean that human chess players do something that cannot be duplicated by a machine, something that does not rely on brute force. Indeed, he goes on to grant that no machine can truly replicate the human mind, since such a machine would have to embody the whole experience of the human race—a clear impossibility. But is this not tantamount to saying that even if consilience were in some sense true, for practical purposes it is useless? Or, to put it another way, that consilience is in the end not a scientific doctrine but a theological one?

For myself, although of course I cannot prove what I am about to say, I do not believe there is a Theory of Everything—not even of something as “simple” as physics. Einstein himself got nowhere when he set his sights too high, and other physicists who make the attempt tend to sound almost as shallow as George Wald. The Upanishads tell us to seek the source and not the shapes. Wilson cannot be faulted for seeking the source, but he is a long way from finding it.

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¹ Knopf, 332 pp., $26.00.

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