Political science the study of government and political processes, institutions, and behavior. Government and politics have been studied and commented on since the time of the ancient Greeks. However, it is only with the general systematization of the social sciences in the last 100 years that political science has emerged as a separate definable area of study. Political science is commonly divided into a number of subfields, the most prominent being political theory, national government, comparative government, international relations, and special areas shared with other social sciences such as sociology, psychology, and economics.
In practice, these subfields overlap. Political theory encompasses the following related areas: the study of the history of political thought; the examination of questions of justice and morality in the context of the relationships between individuals, society, and government; and the formulation of conceptual approaches and models in order to understand more fully political and governmental processes.
The study of national government focuses on the political system of the researcher's particular country, including the legal and constitutional arrangements and institutions; the interaction of various levels of government, other social and political groups, and the individual; and proposals for improving governmental structure and policy. Comparative government covers many of the same subjects but from the perspective of parallel political behavior in several countries, regions, or time periods.