Belief as an act of reason

Most philosophers assume (often without argument) that belief is a mental state. Call their view the orthodoxy. In a pair of recent papers, Matthew Boyle has argued that the orthodoxy is mistaken: belief is not a state but (as I like to put it) an act of reason. I argue here that at least part of his disagreement with the orthodoxy rests on an equivocation. For to say that belief is an act of reason might mean either (i) that it’s an actualization of its subject’s rational capacities or (ii) that it’s a rational activity (hence, a certain kind of event). And, though belief is not an act of reason in the second sense, it may nonetheless be one in the first: it may be a static actualization of its subject’s rational capacities.