Abstract

David Hume famously criticized rationalist theories of practical reason, arguing that reason alone is incapable of yielding action, and that some passionate element must be supplied. Contemporary theories of Humean inspiration develop a causal-explanatory model of action in terms of the joint operation of two distinct mental states: beliefs and desires, one inert and representational, the other dynamic. Such neo-Humean theories claim that since desires, unlike beliefs, are not subject to direct rational evaluation, an act can be said to be rational only in the sense that it is instrumental to realizing the agent’s desires. The historical Hume appears to have embraced a “sceptical solution” involving a more dynamic conception of belief, while admitting a default sense in which both beliefs and actions can be deemed reasonable or unreasonable.