Kenneth W. Simons, Self-Defense: Reasonable Beliefs or Reasonable Self-Control?, 11 New Crim. L. Rev. 51 (2008).
The reasonable person test is often employed in criminal law doctrine as a criterion of cognitive fault: Did the defendant unreasonably fail to appreciate a risk of harm, or unreasonably fail to recognize a legally relevant circumstance element (such as the nonconsent of the victim)? But it is sometimes applied more directly to conduct: Did the defendant depart sufficiently from a standard of reasonable care, e.g. in operating a motor vehicle, that he deserves punishment? A third version of the reasonable person criterion, which has received much less attention, asks what degree of control a reasonable person would have exercised. Many criminal acts occur in highly emotional, stressful, or emergency situations, situations in which it is often both unrealistic and unfair to expect the actor to formulate beliefs about all of the facts relevant to the legality or justifiability of his conduct. A "reasonable degree of self-control" criterion is sometimes the best criterion for embracing these contextual factors.
In self-defense, for example, it is conventional to ask whether the actor believes, and whether a reasonable person would believe, each of the following facts: (a) an aggressor was threatening him with harm, (b) that harm would be of a particular level of gravity, (c) his use of force in response would prevent that harm, (d) the level of responsive force he expects to employ would be of a similar level of gravity, (e) if the force was not used, the threatened harm would occur immediately, and (f) no nonviolent or less forceful alternatives were available whereby the threat could be avoided. United States law typically requires an affirmative answer to each of these questions. Yet in many cases, an actor threatened with harm will actually have no beliefs at all about most of these matters. It would be unfair to deny a full defense to all such actors. At the same time, we should still hold such an actor to a normative standard of justifiable behavior. Specifically, this essay suggests that we reformulate the reasonableness criterion and require this type of actor to exercise a reasonable degree of self-control in response to a threat of force.