This thesis aims to advance the study of cognitive science by examining the “levels metaphor.” The levels metaphor is defined as the application of levels talk to various aspects of scientific investigation. The thesis examines several applications of the levels metaphor within cognitive science and provides a conceptual framework for analyzing discussion. The thesis argues for a pluralistic approach to levels. The main claim is that different applications of the levels metaphor are justified insofar as attention is paid to how and why the metaphor is deployed. To show that my approach has practical applications, I discuss the role of levels within computational cognitive modeling.