The General Principles of Avicenna's `Canon of Medicine'

discussion of the various possibilities and it is not unlikely that it was from this or the writings of Sennert's contemporary opponents that Harvey derived a knowledge of the projectile-theory. For this formed a stock-piece in coeval dissertations on generation. Impetus, then, as far as used by Harvey, is not necessarily bound up with the scientific revolution in physics and mechanics or any theory underlying it. For it is difficult to overrate the vitalist tenor of Harvey's propositions. Moreover impetus is not the only link by which his biological ideas are connected or can be visualized as an organic whole. To mention only a few of the most pregnant of Harvey's ideas, there is the concept of working-matter, the concept of circularity, of immanence and of centralization. The merit of the book under notice would, then, lie in the first place in a number of penetrating analyses of Harveian physiological concepts. In this respect the emphasis laid by the author on the relationship between heat and motion calls for particular attention: in Harvey's view heat is generated and maintained by motion and this helps to understand much that is said and implied in De motu. Heat and motion are further shown to be exchangeable: motion engenders heat, but heat also gives rise to motion. This mutuality is presented as significant in the initiation of life in the fertilized germ. The demonstration of the roots of the idea that heat is generated by motion in ancient and notably Aristotelian cosmology and of similar contemporary notions to Harvey is of additional value. In the second place the work must be appreciated as a serious search for a conceptual link between what sounds mechanistic in Harvey on the one hand and what makes him a determined vitalist of the Aristotelian stamp on the other. This has been attempted through a sustained examination of one of such conceptional links. Inevitably one of the best by-products of this is the defence of Harvey's Aristotelian method. It is here presented as a factor that places Harvey among the leading spirits of his century. For the contention that aggregation and sorting out of facts, that mere induction and the 'clumsy office-clerk methods' (unbeholfene Kanzlisten-methoden) of Sir Francis Bacon have launched modem science is, as the author says, behind the times. Harvey, by contrast, developed a constructive and specific biological method which enabled him to anticipate modem tendencies …