Defending internalists from acquired sociopaths

Abstract

People who suffer brain damage to their ventromedial prefrontal cortex (VM patients) have a puzzling psychological profile: they seem to retain high intellect and practical reasoning skills after their brain injuries, but continually make poor decisions in many aspects of their lives. Adina Roskies argues that their behavior is explained by the fact that, although VM patients make correct judgments about what they ought to do, they are entirely unmotivated by those judgments. Roskies thus takes VM patients to be real-world counterexamples to motivational internalism: the thesis that, necessarily, if S judges that she ought to φ in circumstances C, then S is somewhat motivated to φ in C. In this paper, however, I argue that the neuropsychological evidence that Roskies appeals to does not actually show that VM patients are entirely unmotivated by their normative judgments. Rather, I argue, the evidence suggests that VM patients form weaker normative judgments than normals during practical deliberation. And this affords the internalist with a plausible explanation for VM patients’ behavior: because VM patients form weaker normative judgments than normals, they are less motivated by their normative judgments than normals, which allows their decision-making to be overruled by their standing desires for greater and more immediate rewards.