Ventromedial prefrontal cortex lesions and motivational internalism

This article discusses the argument by Roskies to the effect that ventromedial prefrontal cortex (VMPFC) patients are a living counterexample to motivational internalism. Motivational internalism is a philosophical position according to which moral judgments are accompanied by a particular motivational force that induces agents to act accordingly. Roskies takes into account a very strong version ofmotivational internalism and claims that this version is defeated by the existence of VMPFC patients, who are able to make moral judgments but fail to be motivated accordingly. Violations of moral norms can be caused by a lack of moral motivations, by a lack of nonmoral motivations to respect those rules, or by a conflict between nonmoral motivations to violate and motivations to stick to the rule. I accept that VMPFC patients carry out moral judgments, but I believe that nothing so far proves that VMPFC patients lack moral motivations, as their behavior is not immoral and conformity to moral rules can be caused by nonmoral motivations too. Hence, Roskies’s argument against motivational internalism fails as she cannot show that the patients’ behavior is caused by a lack of moral motivation.