Full Idea
According to the standard picture of human psychology that we get from Hume, not only are desires not assessable in terms of truth and falsehood, they are not subject to any sort of rational criticism at all.
Gist of Idea
In the Humean account, desires are not true/false, or subject to any rational criticism
Source
Michael Smith (The Moral Problem [1994], 1.3)
Book Reference
Smith,Michael: 'The Moral Problem' [Blackwell 1994], p.8
A Reaction
This is where action theory meets metaethics. The separation of facts from values underlies this, because a desire is a fact, but the wickedness of a desire is not. Surely a desire could be a failure of practical reason?
Related Idea
Idea 23724 A pure desire could be criticised if it were based on a false belief [Smith,M]