Full Idea
Only the Humean theory is able to make sense of reason explanation as a species of teleological explanation, and one may accept that reason explanations are teleological without accepting that they are causal.
Gist of Idea
Reasons can give purposes to actions, without actually causing them
Source
comment on Donald Davidson (Action, Reasons and Causes [1963]) by Michael Smith - The Moral Problem 4.6
Book Reference
Smith,Michael: 'The Moral Problem' [Blackwell 1994], p.113
A Reaction
That is, reasons can give a purpose to an action, and thereby motivate it, without actually causing it. I agree with Smith. I certainly don't (usually, at least) experience reasons as directly producing my actions. Hume says desires are needed.