A Sufficientist Approach to Reasonableness in Legal Decision-Making and Judicial Review

Abstract

I shall argue for a sufficientist understanding of reasonableness in legal decision-making: cognitive or moral optimality are not required for reasonableness; what needed is just that a determination—be it epistemic or practical—is sufficiently good (acceptable, or at least not unacceptable). Correspondingly, judicial review on the ground of unreasonableness requires more than mere suboptimality: it requires failure to achieve the reasonableness threshold. To develop this idea, I shall first analyse the notions of rationality and reasonableness, examining the role they play in cognition. I shall then consider rationality in legal (and in particular legislative) decision-making, focusing on teleological reasoning. I shall consequently develop an idea of sufficientist reasonableness, by combining the idea of bounded rationality with the idea of deference, as required by institutional coordination in the legal process. Finally, I shall consider when a legislative determination can be considered irrational or unreasonable, and how this is related to the violation of constitutional requirements.