This distinction is not an exclusive one. In a
class on American government, for instance,
students learn not only how Congress, the
presidency, interest groups, and the like actually
function but also about the normative grounds
underlying the existence of representative
institutions and other elements of modern
democracies. The description of the world as it is
can, in principle, coincide with arguments
concerning how it ought to be organized. At this
juncture political science and political philosophy
meet.