Should We Have Lay Justices

By "lay justices" I mean justices of the Supreme Court of the United States who are not accredited lawyers. Currently the number of lay justices is zero, although there is no constitutional or statutory rule that requires this. Commentators who urge that the Supreme Court should be diverse on all sorts of margins - methodological diversity, ideological diversity, and racial or ethnic or gender diversity - say little or nothing about professional diversity on the Court. I argue that the optimal number of lay justices is greater than zero. In the strong form of the argument, an historian, economist, doctor, accountant, soldier or some other nonlawyer professional should be appointed to the Court. In a weaker form of the argument, we should at least appoint dual-competent justices - lawyers who also have a degree or some other real expertise in another body of knowledge or skill.