Constructivists must be counted among those scholars who conceive research as a matter of interpretation rather than explanation. Moreover, they have a substantial skepticism about the possibility of having a neutral attitude towards research. In the study of national security, the emphasis is on the conditioning that culture and identity exert on security policies and related behaviors. Identities are necessary in order to ensure at least some minimal level of predictability and order, as Hopf asserts in his studies. The object of the constructivist discourse can be conceived as the arrival, a fundamental factor in the field of international relations, of the recent debate on epistemology, the sociology of knowledge, the agent/structure relationship, and the ontological status of social facts.