Peter Matthiessen occupies a unique position in contemporary letters. In the more than three decades since the publication of his first book, a novel called Race Rock (1954), he has received a good deal of attention for his contributions to two seemingly very distinct literary genres. Some readers know him primarily for his fiction—especially for the two longest, most recent, and most accomplished of his five novels, At Play in the Fields of the Lord (1965) and Far Tortuga (1975)—while some are more familiar with his nonaction writings on man and nature, a dozen-odd books with titles like The Cloud Forest, Under the Mountain Wall, The Tree Where Man Was Born, and The Snow Leopard. His work in both genres has been awarded recognition at a high level: At Play in the Fields of the Lord and The Tree Where Man Was Born were each nominated for the National Book Award, and The Snow Leopard won it; in the past two years, moreover, Random House has done him the honor of reprinting all of his novels, and his most recent book of nonfiction, in a handsome, uniform series of Vintage paperbacks.¹ Patently, to even a cursory observer, this is an impressive, not to say a prepossessing, résumé: how many living American writers, after all, have distinguished themselves in two such disparate fields as natural history and the novel?

As one looks more closely at Matthiessen’s oeuvre, however, these fields begin to seem less