The scientific revolution is a many-faceted realization of Kuhn's phylogenic tree (1962), whose trunk is ancient astronomy with ramifications into terrestrial physics (Galileo, Descartes. Huygens, Newton) and biology and medicine (Aristotle, Galen, Vesalius, Harvey, Descartes, Steno, Linnaeus, Darwin, Fisher,Morgan, Mayr, Rapp). 'Revolutions' of the sort documented in Kuhn's Structure (1962) are pervasive in the history of science, both physical and biological. Some of these are analyzed in this book , but continuity within a tradtion is sought. As Kuhn argues in The Copernican Revolution (1959), scientific change is gradual with overlapping concepts and ideals, so discovery can be the rational pursuit of an ideal recognized as yet unfulflled.