  An important variant of action-based theories of desire holds that desires are mental states that have the function of producing actions, rather than mental states that merely dispose agents to act. On these theories, a desire might or might not dispose an actor to satisfy the desire, but causing that result is the job or purpose of the desire (the biological function of the desire), or bringing about the satisfaction of the desire is how the action-production systems do their jobs or fulfill their purposes (Millikan 1984; Papineau 1987). While these variations do well with Stampe-type objections (because it is not the purpose of a belief that one is going to double fault to cause a double fault), they nonetheless would seem to be subject to objections by those who think that beliefs in the good can also perform their functions by moving one to act.