I HAVE LANDED: The End of a Beginning in Natural History, by Stephen Jay Gould. Harmony, 432 pp. 

Like the character in a play by Moliere who was pleased to learn that he had been speaking prose his whole life, Stephen Jay Gould determined at some point that his columns for the magazine Natural History were, in fact, essays. They had a literary pedigree. By Gould's own account, this discovery came as a relief. His use of the first-person pronoun and his references to history and literature, while at best peculiar by the standards of scientific writing, were embedded in the genetic code of the essay as a genre, which emerged during the Renaissance. That was well before the sciences and the humanities had polarized into "the two cultures," speaking mutually unintelligible jargons. Indeed, the root sense of "essay"--deriving from a French verb meaning "to test"--suggests not just literary performance but laboratory experiment.

Between 1974 and 2001, when the last of his Natural History columns appeared, Gould published 300 monthly columns, along with scientific books and papers, plus occasional pieces for other magazines. I Have Landed is the 10th collection of Gould's essays. It appears at roughly the same time as The Structure of Evolutionary Theory, his scientific magnum opus--a systematic analysis of how Darwinian theory has guided, and in turn been reshaped by, biological and paleontological research. Structure is some 2,500 pages long, and other scientists will undoubtedly consult it, or at least feel like lazy sods in its presence, for years to come.

With Gould's most recent volume of pieces, I have the impression--reinforced by readings of some earlier collections--that he has doubled his bid for immortality by building, in effect, a second monument. His essays cohere. They are all over the map (from Gilbert and Sullivan and the human genome to syphilis and Sept. 11) without being merely miscellaneous. There are layers of cross-reference among the separate pieces that can be recognized only upon rereading. His style is a wonder. The expression "creative nonfiction" has become an embarrassment: So much of what has been fostered under that heading involves documentation of the writers' feelings of specialness. But if the term could be revitalized, Gould's essays would be the ideal example of creative nonfiction.

On first encounter, it bears a generic similarity to the work of, say, Martin Gardner or Isaac Asimov: someone with a scientific background with the rare gift for introducing laypeople to matters they might otherwise find inaccessible. Yet that resemblance is misleading. Gould's columns are not really examples of science reporting (that rarest of journalistic competencies). Nor is Gould exactly a popularizer. Many of the essays, especially the ones on Darwin or the early history of paleontology as a discipline, are based on original scholarly research. They could well have appeared in academic journals, had he been willing to provide footnotes and write badly.

In a previous collection, Gould offered his own take on the old-fashioned expression "natural history," redefining it (and hence the scope of his essayistic work) as "the history of how humans have learned to study and understand nature." His most characteristic approach to chronicling that history is intellectual biography: brief but detailed character sketches offering "the distilled essences of the central motivations and concepts of interesting and committed scholars and seekers from all our centuries and statuses." He has done portraits of several naturalists of the Victorian age; in his new collection, Gould tries to figure out how E. Ray Lankester, a highly respectable biologist of that era, ended up as one of the handful of mourners attending the funeral of Karl Marx. And his interest returns constantly to Darwin's work--the paradigm decisively shaping our understanding of what nature and humans have to do with each other.

But what Gould also does, and does uniquely well, is explore the history of untenable ideas. There have been theories about nature that, like countless species along the evolutionary way, simply died off. A few hundred years ago, doctors treating a wound with ointment also made sure to annoint the weapon that inflicted it. Theologians trying to figure out inconsistencies in Genesis speculated that God might have created some pre-Adamic peoples (sort of a warm-up exercise perhaps); if you squint, their efforts look something like evolution. And in a manuscript discovered only in the 1980s, Sigmund Freud elaborated some formidably peculiar theories of his own concerning human prehistory.

Gould manages to discuss these ideas without the usual sarcasm or rolling of the eyeballs. "To unravel the archaeology of human knowledge," he writes, "we must treat former systems of belief as valuable intellectual 'fossils,' offering insights about the human past, and providing precious access to a wider range of human theorizing only partly realized today." This is, however, a perspective quite distinct from the laissez-faire attitude of New Age relativism, for which quantum physics and astrology are both "true," sort of. Bad ideas die for good reasons. (You can't keep a wound from festering by spraying antiseptic on the knife, nor does evidence support Freud's idea that the Ice Age rendered humanity neurotic.) But the record of their birth, development and extinction has its place in natural history.

In a revealing passage, Gould takes aim at a dubious notion that is by no means dead, but is, rather, commonplace, if unstated: the assumption that there is "a fixed and limited amount of 'stuff' available for each intellect." (He does not call this "the theory of finite gray matter," but that would fit.) According to this idea, "if we assign too much of our total allotment to the mastery of detail, we will have nothing left for general theory and integrative wonder. But such a silly model of mental functioning can only arise from a false metaphorical comparison of human creativity with irrelevant systems based on fixed and filled containers--pennies in a piggy bank or cookies in a jar."

Or as someone else once put it: When you use your mind, you don't use it up. But for most people interested in literature (or history or philosophy), there is no risk of any gray matter's being burdened with scientific knowledge, whether at the level of minute detail or grand theory. We avoid that danger quite successfully. There are plenty of things to learn from reading Stephen Jay Gould, but one of them really sticks with you: the realization that, in regard to understanding the natural world, the most sophisticated litterateurs tend to be, more or less, small children, only without the child's saving grace of curiosity.