Epistemic constitutionalism Questions of fact and the need for evidence in principle-based reasoning

In this paper, I argue that two types of reasoning often regarded as pertaining only to questions of law actually require addressing questions of fact as well. The first of these occurs when we argue that a rule cannot apply to a concrete case because doing so would be contrary to the rule's purpose. The second is the reasoning required to apply the proportionality test. More specifically, I maintain that each of the three steps of the proportionality test (suitability, necessity, and proportionality in the narrow sense) requires the justification of a factual premise that is easily neglected. If this is correct, it follows that judges, and especially constitutional judges, should explicitly engage in evidentiary reasoning more than they currently do, clarifying the burdens of proof and standards of proof they are applying. I also argue that if a culture of fact-finding developed in the application of legal principles following my suggestion, this could help build a virtuous dialectic between the judiciary and the legislature and enhance the rationality of public debate on legislation.