AbstractIn this article I consider the impact of social epistemologies for understanding the object of the syringe. My aim is to examine the process through which the syringe transforms from an injecting device to a tool of social and political inquiry. Paying particular attention to the uses ofFoucault,Becker,Bourdieu,Freud andLatour in empirical studies of injecting heroin use, I examine the sociology of the syringe through the lens of habit and habitus, discourse and deviance, mourning and melancholia, attachment and agencement. In pursuing the theory behind the object my goal is to address a sociological object in the making. In so doing I show how the syringe has been significant for social research, social theory, and sociology. It is the difference the object makes that this article seeks to describe. In tracing the epistemology of the syringe I show how the object is important not just for knowledge of addiction but sociology itself.