The study of politics and political life. Originally it concentrated on the state and how it was organized, but more recently it has come to include the analysis of all those institutions and groups which possess and exercise political power.
Many philosophers, including Aristotle, Thomas Hobbes, and J J Rousseau, have been concerned with defining the political institutions that are held necessary for a properly functioning civil society. Political science, however, differs from political philosophy or political theory in being descriptive rather than prescriptive, more concerned with how political institutions actually function than with how they ought to function.