[The essay from which this excerpt is taken originally appeared in 1979 as an introduction to Peter Matthiessen, A Bibliography: 1951–1979, compiled by D. Nichols.]

I read Partisans and Raditzer with the same careful eye that I had Race Rock; as talented and sensitive as each appeared to be, the statement of a writer at the outset of his career, they were, I felt, merely forerunners of something more ambitious, more complex and substantial—and I was right. When At Play in the Fields of the Lord was published in 1965 there was revealed in stunning outline the fully realized work of a novelist writing at white heat and at the peak of his powers; a dense, rich, musical book, filled with tragic and comic resonances, it is fiction of genuine stature, with a staying power that makes it as remarkable to read now as when it first appeared.

But before...