<P> Some political science departments also classify methodology as well as scholarship on the domestic politics of a particular country as distinct fields . In the United States, American politics is often treated as a separate subfield . </P> <P> In contrast to this traditional classification, some academic departments organize scholarship into thematic categories, including political philosophy, political behaviour (including public opinion, collective action, and identity), and political institutions (including legislatures and international organizations). Political science conferences and journals often emphasize scholarship in more specific categories . The American Political Science Association, for example, has 42 organized sections that address various methods and topics of political inquiry . </P> <P> As a social science, contemporary political science started to take shape in the latter half of the 19th century . At that time it began to separate itself from political philosophy, which traces its roots back to the works of Chanakya, Aristotle, and Plato which were written nearly 2,500 years ago . The term "political science" was not always distinguished from political philosophy, and the modern discipline has a clear set of antecedents including also moral philosophy, political economy, political theology, history, and other fields concerned with normative determinations of what ought to be and with deducing the characteristics and functions of the ideal state . </P>

When did political science become an academic discipline