THE SAME AND NOT THE SAME.

By Roald Hoffmann. Columbia Univ. Press. 294 pp. $34.95

Goethe modeled his novel Elective Affinities(1809) on a theory about the spiritual origins of chemistry. In a similar vein, Hoffmann-chemist, poet, and Nobel laure- ate-wishes to show how the activities of molecules "parallel deep avenues in our psyche."

The book's allure is based on metaphor, as Hoffmann draws a parallel between the oppositional properties of molecules and the dualities of human relationships: bonding and separation, continuity and change, the natural and the unnatural. Playfully, he explores the fact that some molecules are mirror images of one another, "the same and not the same," like the molecules creating the smells of spearmint and caraway. More ominously, the disastrous sedative thalidomide is deceptively similar to two other successful compounds.

Hoffmann's evident ambition is to make a case for chemistry to supplant physics as the philosophical model for all the sciences. His arguments are that chemistry is creative as well as analytic, and that, compared with physics, chemistry deals more interestingly with conflict and ambiguity.

Evident also is the author's hope that his book will do for chemistry what Stephen Hawking's wildly successful Brief History of Time did for astronomy. But Hawking's book, for all its difficulties, has a clear narrative line leading from the early development of astronomy to its later achievements and ultimate speculations.

Hoffmann's book, by contrast, mixes lucid explication with a great many frag- mentary jottings that lead nowhere. Such open-endedness may be helpful when examining molecules, but in writing it defeats coherence.

-Susan Ginsburg