 A powerful philosophical picture of human psychology, stemming from Hume, insists that beliefs and desires are distinct existences (Hume 2000, Book II, part iii, sect. iii; cf. Smith 1994, 7). This means that there is always a potential problem about how reasoning, which seems to work by concatenating beliefs, links up to the motivations that desire provides. The paradigmatic link is that of instrumental action: the desire to Ψ links with the belief that by Φing in circumstances C one will Ψ. Accordingly, philosophers who have examined moral reasoning within an essentially Humean, belief-desire psychology have sometimes accepted a constrained account of moral reasoning. Hume’s own account exemplifies the sort of constraint that is involved. As Hume has it, the calm passions support the dual correction of perspective constitutive of morality, alluded to above. Since these calm passions are seen as competing with our other passions in essentially the same motivational coinage, as it were, our passions limit the reach of moral reasoning. 