Simply asking the question "Is God dead?" once made sales of Time magazine skyrocket. The issue was even broached in Roman Polanski's popular, modern film classic Rosemary's Baby. But, in the end, raising the provocative question hardly changed anyone's views on the matter. These days, most people who want to know about human nature do not turn to Time, or the Book of Genesis or the Ramayana. They tend to satisfy their existential hunger by reading "Science and Health" columns and by contemplating descriptions of the skulls of hominid ancestors toasted in the African sun, topped with assorted genes.

We now try to explain ourselves by announcing the discovery of new genes, such as one for shyness ("was hard to clone, hid behind other genes," researcher says), and by developing respectable but often incomprehensible philosophies of mind. How do we appear in this picture? Kenan Malik considers the answer in his book Man, Beast and Zombie: What Science Can and Cannot Tell about Human Nature.

On page 22 of his 600-page book, Malik asks "What data have scientists produced about human origins, human behavior, the human mind, and so on? What is . . . being said through particular interpretations of this data?" He then proceeds to examine the scientific arguments, their philosophical background, and how they were influenced by past cultural and intellectual changes. His effort is both scholarly and well written. And it's the best of all attempts to see what science has had to say on this broad subject.

Later, he introduces the Beast and the Zombie. The Beast embodies the vision of humans proposed by sociobiology and evolutionary psychology - disciplines that look at man from the perspective of evolution. Man the animal, not "created in the likeness of God," but spawned by the Grim Reaper of natural selection and "Nature, red in tooth and claw." Since Darwin's Origin of Species, the gap between humanity and animals has shrunk enormously. With toolmaking chimps and intelligent shrimps on one side and selfish genes on the other, science made beasts more humane, and humans more beastly.

How beastly exactly? For a long time after World War II, nobody dared to ask the question, out of fear of awakening the ghost of Fascists, who perverted Darwinian ideas and used them to justify their atrocities. The taboo was strengthened by feelings of guilt. Social Darwinism, with its racist and chauvinist overtones, was popular not only in Germany, but all across the United States and Europe. My own Eastern European country, Poland, had followers of this heinous abuse of Darwin's work.

When the question of the Beast in humankind was raised again in 1975 by E. O. Wilson in his book Sociobiology: The New Synthesis, it provoked some of the harshest and most uncivilized quarrels in academia. Disputes involved branding opponents as "Nazi reactionaries" (pro-sociobiology) or "Commie ideologists" (anti-sociobiology). Man, Beast and Zombie, What Science Can and Cannot Tell about Human Nature provides a colorful description of these unseemly arguments. We see Wilson assaulted by leftist students. And we hear about George Price, the scientist who helped to coin the "selfish gene" equation. Price was horrified by its implications and he eventually killed himself with a pair of scissors.

Remarkably though, Malik is not a partisan of any of the warring factions. Instead, he carefully scrutinizes the three main approaches used by sociobiologists: making inferences from pressures imposed on our cave-dwelling ancestors by natural selection, comparing humans to "other monkeys," and looking for common denominators across different human cultures, especially the so-called "primitive" ones.

While applying scientific rigor to a discipline renowned for making far-fetched claims may provide some progress, upon scrutiny, it turns out that the evolutionary approach nevertheless is ridden with difficulties. For example, contemporary hunter-gatherers such as the !Kung of the Kalahari Desert are not primordial cavemen. They have been "spoiled" by past interactions with farmer societies. The whole idea of a single "primordial human," Malik points out, is, by itself, dubious. Extrapolation from animal to human behavior, is also a slippery business, as one has to compare chimpanzee fights with a baffling range of human behaviors, from playground bullying to the Holocaust.

Yet the criticism is tempered, and Evolutionary Psychology gets praise when it is deserved. Let's hope that with time, this carrot-and-stick approach will make the Beast a respectable academic subject. The field is still young, and all we need, as the primatologist Frans de Waal said "is a more enlightened type of Darwinism that integrates the effects of learning and the environment. It's not as though natural selection dictates specific behavior under all circumstances, it rather induces tendencies."

Because we have minds as well as instincts, cognitive science is the second major topic of the book. Here we meet the Zombies, Gimboes and Qualia. These creatures represent a thought experiment designed to solve the problem of subjective states of mind. Just try to imagine if, one day, your friend told you she is not conscious at all. Would you believe her? And please do not get paranoid that "even your closest ones could be zombies!" as the philosopher Daniel Dennett wrote in a tongue-in-cheek critique of "zombiologists."

This and other thought experiments are supposed to help us grapple with problems of consciousness, subjectivity, and artificial intelligence, and Malik weaves them into a fascinating story. He also challenges the popular view that the mind can be fully explained only by what goes on inside the brain. "The world is made meaningful not just by what goes on in your head, but also by what goes on outside it. . . . It is language and culture that turn brain into mind." The mind, Malik argues, is an "extended mind."

Man, Beast and Zombie is long and not an overnight read. But readers who choose to skip the stage-setting chapters two to five, before the Beast and the Zombie are introduced, will miss some delightful stories. For example, the 19th century physicist Auguste Comte believed so much in the power of science to explain everything that he set up a "Positivist" religion with clergy, catechism, calendar, holidays, and chapels! And the philosophical and historical perspective is very useful. Science responds to the spirit of the times, and "theories of human nature never die. They just go in and out of fashion," as John Horgan has put it.

Is it possible that old theories come back in new clothes because none of them are ultimately satisfying? Science is the very flower of human reason, a clear sign of its strength. Yet according to some, our reason is weak, and we're just ordinary animals. There's something paradoxical here that researchers can't grasp. Science cannot give us the full story. If you want to know what it can offer, check out this masterfully written book.