This article does not aim to describe the opposing views and argue for one over the other. Rather, I propose to deflate the debate as far as possible, attempting to reduce the area of disagreement. Meaningful disagreement exists only if there are, or could be, agents who have an undiminished capacity for practical reasoning or rational self-governance, yet truly are incapable of moral reasoning. However, I suggest that the capacity for rational self-governance entails the capacity to comprehend and act on moral considerations; thus, to the extent that an individual truly is incapable of grasping moral reasons, we should expect to find deeper, more general deficiencies in that individual's rational capacities. I appeal to the work of leading researchers who study individuals with psychopathy to determine whether psychopaths do represent rational self-governors without the capacity to grasp moral considerations. I argue that this work strongly suggests that the psychopath's incapacity for moral reasoning is, indeed, evidence of more general deficits in the rational capacities required for fully accountable agency. The article closes with relevant considerations for thinking about any implications for criminal law.
Paul Litton, Responsibility Status of the Psychopath: On Moral Reasoning and Rational Self-Governance, 39 Rutgers L.J. 349 (2008)