This article revisits the debate over general theory in historical sociology with the goal of clarifying the use of this kind of theory in empirical research. General theories are defined as postulates about causal agents and causal mechanisms that are linked to empirical analysis through bridging assumptions. These theories can contribute to substantive knowledge by helping analysts derive new hypotheses, integrate existing findings, and explain historical outcomes. To illustrate these applications, the article considers five different general theories that have guided or could guide historical sociology: functionalist, rational choice, power, neo-Darwinian, and cultural theories. A key conclusion that emerges is that scholars must evaluate both the overall merits of general theory and the individual merits of specific general theories.