Modern science, it has been said, has undergone three revolutions: the Copernican, the Newtonian, and the Darwinian. This oversimplification is valid if our standard of judgment is social impact. The Newtonian synthesis, which absorbed the Copernican, had convinced men that the physical universe behaved in accordance with inviolable natural laws and that these laws could be expressed mathematically. With the confidence inspired by this world picture, science sought to find those natural laws under which the animate and inanimate aspects of the world operated. Equally influential was the tradition which cherished the ideal of the conquest of nature through the utilization of scientific knowledge. The many discoveries and inventions of the eighteenth century lent assurance and optimism to the prevailing attitude. The present chapter relates some of the divergent influences which merged into the Darwinian synthesis: biological evolution. [excerpt