Amusing final sentence from Clarke & Primo (2005):

While much ink has been spilled arguing for this approach to the study of political science, little attention has been paid to justifying and rationalizing the method. On the rare occasions that justification has been attempted, the results have been maddeningly vague. Why test predictions from a deductive, and thus truth-preserving, system? What can be learned from such a test? If a prediction is not confirmed, are assumptions already known to be false to blame? What precisely is the connection between a model and a theory? These questions are never addressed in a satisfactory way.

Some will no doubt argue that such justifications are fruitless and that we should just "get on" with the business of doing science. Philosophical discussions should affect political scientists no more than political scientists affect policy makers...