CONTENTS.PAGE.I.[Darwinism]7II.[Marxism]16III.[Marxism and the Class Struggle]19IV.[Darwinism and the Class Struggle]22V.[Darwinism Versus Socialism]27VI.[Natural Law and Social Theory]33VII.[The Sociability of Man]36VIII.[Tools, Thought and Language]42IX.[Animal Organs and Human Tools]50X.[Capitalism and Socialism]54MARXISM and DARWINISM