Motivation and Reasons Externalism

Humean Theory of Reasons (HTR):  Reasons reduce to desires.

Also known as Reasons Internalism.  If a person doesn’t have a desire for something, then they have no reason to do it.

Humean Theory of Motivation:  Desires are necessary and beliefs are not sufficient for motivation.  Beliefs cannot motivate on their own.

It seems to follow that if one has no desire to do A then one has no reason to do A.  

Shafer-Landau holds that these theses lead to the Non-Cognitivist Argument for moral anti-realism: 

1. Necessarily, if one sincerely judges an action right, then one is motivated to some extent to act in accordance with that judgment. (Motivational Judgment Internalism)
2. When taken by themselves, beliefs neither motivate nor generate any motivationally efficacious states. (Motivational Humeanism)
3. Therefore, moral judgments are not beliefs. (Moral Non-cognitivism)

We can deny 1 or 2.  A person can make a sincere moral judgment and be left cold and unmotivated to perform it - this requires the possibility of the amoralist.  Or, beliefs can motivate all by themselves - perhaps normative type beliefs?  Kant took this option. 

Moral Rationalism:  If something is morally wrong then that entails that there is a reason not to do it.

Philippa Foot denied Moral Rationalism in rejecting Categorical Imperatives.  She would hold that what Hitler did was wrong even though he had no reason not to do it.

Moral Absolutism: Some actions are morally wrong for any agent no matter their desires or motivations. 

If we take HTR, Moral Rationalism, and Moral Absolutism, we get the Central Problem:
It was wrong for Hitler to commit genocide, even if it was his desire.
If, as MR holds, its wrong for Hitler to commit genocide only if there’s a reason for him not to do it, and
If, as HTR holds, there is a reason for him not to do it only if he has some desire against it,
Then it follows that whether an action is morally wrong for an agent depends on what he desires.
But that contradicts Moral Absolutism.

And this is the central problem.  So we must reject HTR, Moral Rationalism, or Moral Absolutism.  

I think we should reject HTR.  An agent can have a reason to do something whether or not he desires it.

If one admits Categorical Imperatives and Moral Rationalism, then they are committed to Reasons Externalism.

If one admits that moral beliefs can be non-motivating, then they are motivation externalist.  They believe the amoralist is a possibility.