Political philosophy, also known as political theory, is the study of topics such as politics, liberty, justice, property, rights, law, and the enforcement of laws by authority: what they are, if they are needed, what makes a government legitimate, what rights and freedoms it should protect, what form it should take, what the law is, and what duties citizens owe to a legitimate government, if any, and when it may be legitimately overthrown, if ever.
Political science is generally used in the singular, but in French and Spanish the plural (sciences politiques and ciencias políticas, respectively) is used, perhaps a reflection of the discipline's eclectic nature.Political theory also engages questions of a broader scope, tackling the political nature of phenomena and categories such as identity, culture, sexuality, race, wealth, human-nonhuman relations, ecology, religion, and more.
Political philosophy is a branch of philosophy, but it has also been a major part of political science, within which a strong focus has historically been placed on both the history of political thought and contemporary political theory (from normative political theory to various critical approaches).
In the Oxford Handbook of Political Theory (2009), the field is described as: "[...] an interdisciplinary endeavor whose center of gravity lies at the humanities end of the happily still undisciplined discipline of political science ... For a long time, the challenge for the identity of political theory has been how to position itself productively in three sorts of location: in relation to the academic disciplines of political science, history, and philosophy; between the world of politics and the more abstract, ruminative register of theory; between canonical political theory and the newer resources (such as feminist and critical theory, discourse analysis, film and film theory, popular and political culture, mass media studies, neuroscience, environmental studies, behavioral science, and economics) on which political theorists increasingly draw."