This is a groundbreaking and timely collection of papers by Alexander Rosenberg, the distinguished philosopher of science. The essays cover three broad areas related to Darwinian thought and naturalism: the first deals with the solution of philosophical problems such as reductionism, the second with the development of social theories, and the third with the intersection of evolutionary biology with economics, political philosophy, and public policy. Rosenberg's important writings on a variety of issues are here organized into a coherent philosophical framework that promises to be a significant and controversial contribution to the philosophy of science and the application of evolutionary biology to social science and policy.