Introduction

Brilliant as were the flashes of biological insight illuminating this period, the problems of biology were too manifold and too complex to permit the formulation of any comprehensive and stable interpretive structure; many limiting-factors, technical and conceptual, were to be gradually removed only in the nineteenth century. The conceptual and the methodological steps forward in science do not necessarily occur in phase, and a long period of cumulative, undramatic development may sometimes be an essential prelude to a major shift in ideas, to the opening of some new door. Historians have long employed a chronological scheme in which Lavoisier is seen as the 'Newton' of chemistry and Darwin (1859) as the 'Newton' of biology. Perhaps it is not stretching imagination to see practical medicine playing somewhat the same role in the development of biology as that of technology in the evolution of the physical sciences.