Political science is commonly divided into three distinct sub-disciplines which together constitute the field: Political Philosophy, Comparative Politics and International Relations. Political Philosophy is the reasoning for an absolute normative government, laws and similar questions and their distinctive characteristics. Comparative Politics is the science of comparison and teaching of different types of constitutions, political actors, legislature and associated fields, all of them from an intrastate perspective. International Relations deals with the interaction between nationstates as well as intergovernmental and transnational organizations.
Political science is methodologically diverse and appropriates many methods originating in social research. Approaches include positivism, interpretivism, rational choice theory, behavioral, structuralism, post-structuralism, realism, institutionalism, and pluralism. Political science, as one of the social sciences, uses methods and techniques that relate to the kinds of inquiries sought: primary sources such as historical documents and official records, secondary sources such as scholarly journal articles, survey research, statistical analysis, case studies, and model building.
"As a discipline" political science, possibly like the social sciences as a whole, "lives on the fault line between the 'two cultures' in the academy, the sciences and the humanities." Thus, in some American colleges where there is no separate School or College of Arts and Sciences per se, political science may be a separate department housed as part of a division or school of Humanities or Liberal Arts. Whereas classical political philosophy is primarily defined by a concern for Hellenic and Enlightenment thought, political scientists are broadly marked by a greater concern for "modernity" and the contemporary nation state, and as such share a greater deal of terminology with sociologists (e.g. structure and agency).
