The biographer of Claude Bernard (1968) projects Andreus Vesalius with comparable regard for the influence of a time on a life: born in Brussles in 1514, ""the father of modern anatomy"" was very much a product of the burgeoning Italian Renaissance. He studied medicine at the progressive University of Padua where he enjoyed an intellectual freedom denied in the French schools, and where his radical criticism of antiquated Galenism, the Fabrica, was published. It is known that Vesalius served as court physician to two kings, that he believed surgery to be the function of doctors not barbers, and that he propounded a medical science founded on observation not classical logic; information about his character and personality, however, is undocumented and largely derivative. Mr. Tarshis responsibly distinguishes facts from educated assumptions in this first juvenile on the subject, correlating the variegated texture of Renaissance history with Vesalius' pioneer conclusions--most notably in the unusual attention he accords to the Fabrica as a revolution as much in form, concept, and production as it was in content. From the identities of Plato and Aristotle to the conduct of medical dissections, everything here is dealt with easily and knowledgeably; the book's only real flaw is its tendency to repeat overmuch. Excerpts from the Letter on the China Root are appended to ""give the reader an idea of the way Vesalius thought and wrote,"" and although uncommonly interesting they are unnecessary since Mr. Tarshis has already done so expertly.