Toward a Naturalistic Motivational Rationalism

Joshua May (Monash University)

Abstract: Motivational rationalists claim that at least sometimes normative or evaluative beliefs (e.g. beliefs about what one ought to do) can be the ultimate source of one’s motivation. Neo-Humeans, on the other hand, maintain that motivation always ultimately has its source in desire. The dominant trend among philosophers seems to be that rationalistic or generally “anti-Humean” views of motivation are not as compatible with empirical research or scientific approaches to human action (e.g. Mele, Roskies, Schroeder, and Nichols). I investigate how some empirical work, from neuroscience to social psychology, bears on this debate. The focus is limited to neurological disorders (e.g. “acquired sociopathy”) and research on temptation (e.g. “ego depletion”). Perhaps surprisingly, I argue that the evidence is entirely compatible with motivational rationalism and in some cases provides some tentative support for it. While this does not address certain sentimentalist views that eschew the neo-Humean conception of motivation (e.g. McDowell), a decidedly rationalist thesis remains in play.