This paper is about the relationship between political philosophy and politics in liberal democracies. Its broader context is the alleged lack of realism in contemporary liberal democratic theory. Political scientists, and some political theorists who are concerned with a perceived deterioration in the quality of public life, have grown impatient with this supposed failing (Geuss, Newey, Barber). The charges are not new and many have made them. However, little has been said about the key assumption: political philosophy has a significant contribution to make to practical political affairs. I explore the conditions under which this assumption could be true and argue that political philosophy has a role in politics only when it is recruited into political argument. In other words, political philosophy gains political relevance when it becomes part of deliberations and to do that political philosophy must become political rhetoric. Two consequences follow from this. First, the usefulness and, thus, realism of political philosophy is driven by concrete needs of political actors engaged in actual deliberations and not by anything essential to political philosophy. Second, political philosophers can try to make political philosophy relevant to the deliberative aims of political actors, but the more they try, the more they are themselves engaging in a rhetorical, i.e. non-philosophical, mode of discourse. Thus, the argument is constructed on this distinction between the rhetorical and the philosophical and, therefore, on the autonomous relationship between politics and political philosophy.
