What makes Isaac run? What drives this Brooklyn-reared son of Russian-Jewish immigrants to work so assiduously at his typewriter … that he has turned out 199 books in 29 years, thereby earning himself a reputation as one of the leading science-fiction writers and the pre-eminent science popularizer of our day?

Readers who seek the answer to this question will not be disappointed by ["In Memory Yet Green,"] the first volume of Asimov's projected two-volume autobiography. Indeed, he gives the game away early on. Compulsive writers, he makes clear, are made, not born…. (p. 13)

Asimov goes on to detail his writing career…. (He is, as one might guess, an inveterate diarist.) He writes candidly of his relationship with Joan W. Campbell Jr., the editor of "Astounding," whose knack for nurturing young talent was responsible for what has come to be known as the Golden Age of science fiction. He also writes about his first wife, Gertrude, about his friendships in and out of science fiction and about his discovery that he was not a genius (or even particularly adept) in such academic disciplines as mathematics. In all such matters, Asimov never strays very far from the facts. Although he can describe quantum mechanics and resonance theory in a few clear paragraphs, the "soft" sciences, such as psychology, have little appeal for him. (pp. 13, 32)

For any readers unfamiliar with the Asimov oeuvre, "Opus 200" offers a selection of excerpts from his last 100 books (actually, his last 99—Asimov, as he concedes, is not much on math)….

Because Asimov is already hard at work on his next hundred books, it seems almost beside the point to apply the usual critical standards to his output. In an age dominated by science—yet mortally afraid of its practitioners and largely ignorant of its methods—Asimov's compulsion to describe the most arcane discoveries in simple declarative sentences can only be applauded. His aim is clarity, and this he usually achieves. (p. 32)

[An] important question is whether Asimov can possibly be trusted as an authority in so many different fields. Specialists will no doubt find fault with his treatment of individual subjects…. On the whole, however, he has probably done more than anyone else to give scientifically illiterate readers a feeling for the excitement and accomplishments of modern science. (p. 33)