In this essay, I explore two ways of justifying legal rules. The first, which is adopted by some (but only some) academics, justifies legal rules on the basis of comprehensive moral theories; for example, utilitarian or Kantian moral theories. The second way, which is adopted by nearly all judges (though also by many academics), justifies legal rules on the basis of intermediate moral principles, values, or beliefs; for example, fairness, honesty, dignity, reasonableness, keeping one’s word, proportionality, clarity, stability, and predictability.
My exploration focuses on two questions. First, why do judges restrict themselves to ‘intermediate justifications’? The most plausible explanation, I argue, is that, in the pluralist societies that are my focus, for legal rules to be practically effective and, more importantly, for legal rules to be legitimate, they must be acceptable to people who hold different (or no) comprehensive moral theories. And for justifications to be acceptable to such people, they must be limited to intermediate principles. The second question is whether, assuming the ‘acceptability thesis’ (as I will call it) not only explains but also justifies the judicial approach, the thesis also applies to academics. Should academics also limit themselves to intermediate justifications for legal rules? My answer, with certain qualifications, is that they should. Although the ‘practical objection’ to comprehensive justifications has only a limited application to academics, the ‘principled objection’ (the objection from legitimacy) applies with full force. The argument that good justifications for legal rules should in principle be acceptable to people who hold different (or no) comprehensive theories applies regardless of who is offering the justification.
Smith, Stephen, Intermediate and Comprehensive Justifications for Legal Rules (September 6, 2020) in Simone Degeling, Michael Crawford, Nicholas Tiverios (eds), Justifying Private Rights, Hart Publishing, forthcoming.