Prosociality without morality: A Humean constructivist approach to prosocial practical reason for moral skeptics

The moral skeptic frequently encounters the view that without a belief in moral facts she has insufficient justification for acting in prosocial ways, such as acting with concern for the interests or welfare of others. This thesis is an argument against that view. The thesis is in two parts, each employing a different type of philosophy. Part one is empirical philosophy, and draws on evidence from psychology and history to show that morality is neither a necessary nor a sufficient condition of prosociality, and may in fact be an obstacle to it. Part two is in the fields of metaethics and practical reason, and addresses the question of how a moral skeptic can employ rationality to develop robust, stable, and coherent practical reasons for prosociality. I argue that this can be done by employing a Humean constructivist view. Finally, I use John Stuart Mill as a case study, arguing that he is a noncognitivist and thus a moral skeptic, and that a Humean constructivist reading of his utilitarian theory accounts for the harmony between his moral skepticism and his prosocial normative theory. Mill thus offers an example of prosociality and moral skepticism within a Humean constructivist framework.