But to say that no one individual philosopher can expect to do much alone is not to say that political philosophy as such does not achieve anything significant. The prospect of political conversation coming entirely adrift from the reflection of political philosophers is a bleak and chilling scenario. For it is mainly by virtue of the work of such theorists that the terms of political conversation are systematically interrogated and interrelated, and occasionally renewed or replaced. A conversation without any corner for sustained reflection of this kind would quickly run to ground in a babel of dogmatic assertion and counter-assertion. If political philosophers did not exist, we would have to invent them.
-Philip Pettit, Republicanism: A Theory of Freedom and Government