This course provides an examination of the intellectual practice of social science research and theory through the writings of social scientists and philosophers. The emphasis is on comparative and institutional forms of social science and theory. It proceeds from the perspective of an “actor-centered” social ontology. The philosophy of social science is a discipline that analyzes the ontology, methodology, modes of explanation, and methods of inquiry of the social sciences. The past twenty years have witnessed an explosion of valuable debate about foundational issues in sociology and other social sciences. The course is based on the assumption that social research and theory will benefit from a better understanding of the conceptual and methodological issues that arise in the conduct of social science research. Central topics will include social ontology, the role of theories of the actor, theories of causal mechanisms and powers, current thinking about institutions and norms, and the theory of critical realism. The course will make use of recent writings by such social scientists as Andrew Abbott, Peter Hedstrom, Neil Fligstein, Doug McAdam, Kathleen Thelen, Chuck Tilly, and Neil Gross as we explore recent debates about the foundations of social science research and theory.