One can ask two different questions about a given social, political, or legal practice. First, one can ask whether, and if so how, the ideas embodied in that practice explain its development or current prevalence. Second, one can ask whether the practice should be advanced, abandoned, or altered in some way. According to today’s disciplinary conventions, the first question is an historical or explanatory one, whereas the second is a philosophical or normative one.

This essay is about the relationship between these two questions. In particular, it asks the following: How, if at all, do the answers to these questions depend on each other? That is, to what degree, if any, must one evaluate or assess a practice in order to explain its social acceptance? And conversely, how, if at all, should the historical explanation of a practice bear on our normative evaluation of it?

These latter questions – which are really questions about questions – are large and deep ones. They have been long debated by philosophers and historians and are thus ones to which I cannot give conclusive answers. The task of the essay is therefore less to answer them definitively than to suggest what certain answers to them reveal about the modes of reasoning in the disciplines of history and philosophy—and law. It does so by examining a dialogue that took place over several years between the historian Quentin Skinner and the philosopher Charles Taylor. That dialogue nicely illustrates the assumptions of each scholar’s home discipline because both scholars give voice to, yet also challenge, those assumptions. Indeed, I will argue that Skinner and Taylor end up forging common methodological ground with respect to the relevance of historical explanation to philosophical evaluation and vice versa. More specifically, both scholars end up seeing a closer connection between the two disciplines than either historians or philosophers typically do.