(Moral worth cannot come from both concern for morality de dicto and concern for morality de re. Let me explain why not).
Three assumptions, then a definition, then an actual argument. Let’s do the assumptions first:
1. An encouragement-worthy motive is not the same as an esteem-worthy motive, and a moral-worth-granting motive needs to be esteem-worthy. I have used the slightly ambiguous “praiseworthy” all these years – perhaps I’ll stick to “esteem-worthy” this time. At any rate: a Kantian, for example, can hold that sympathy or a sense of honor deserves to be encouraged but consistently also hold that when you act out of sympathy or a sense of honor your action does not have moral worth. You do not deserve esteem for it. 2. The Kantian Principle: a motive cannot grant moral worth if said motive ever leads to unexcused wrong actions. A morally worthy action is done for reasons that make its rightness nonaccidental. If sympathy, for example, leads to wrong actions now and then it would seem to show that sympathy does not have that special connection to rightness that would have made it a moral-worth granting motive. If I help a student out of pure sympathy (whatever Kantians exactly think it is) and my helping the student is a right action then it would seem that in this case, the “sympathetic” thing to do and the right thing to do coincided – very fortunate, as sympathy could also have led me to help students in situations where it would have been wrong. So it would seem that every motive that sometimes would lead to a wrong action cannot grant moral worth, but one needs to be careful – any motive can lead to a wrong action under some excusing conditions. Imagine that the Right Motive tells me to help students in a certain set of possible situations, and I follow that motive, but unbeknownst to me, my student is an unlikely terrorist or an unlikely spy for a fascist regime, and so in helping him, following the Right Motive, I end up doing something wrong – helping a terrorist or a fascist regime. That can happen, but under those conditions I am, presumably, excused from blame – in this case through ignorance of the unlikely situation. So, the Kantian Principle should say: a motive cannot grant moral worth if said motive ever leads to unexcused wrong actions. 3. Ignorance that excuses from blame also “excuses” from esteem. For example, if I have no idea that the money I pay for a trinket goes to a bad organization, I am not blameworthy for contributing to the bad organization. In the same way, if I have no idea that the money I pay for a trinket goes to a good organization, I am not esteem-worthy for contributing to the good organization. If I do not know that the tea I give you is poisonous, I am not blameworthy for poisoning you. If I don’t know that the tea I give you is going to cure your hangover, I’m not esteem-worthy for curing your hangover. And so on.
I will use the term “Huck Finn Case” to refer to any case in which a person does the right thing for the reasons for which it is right (aka “for the right reasons de re“) while thinking that it is in fact a wrong thing to do. It should not matter whether you think the fictional character Huck Finn is in fact a case like that. Note that a Huck Finn Case in my technical sense need not be a case of dramatic akrasia, but simply a case in which someone does something that she believes to be wrong, which is actually pretty common.
1.From the Kantian Principle above: If concern for morality de dicto grants moral worth, then it never leads to unexcused wrong actions.
2. Concern for morality de dicto leads to wrong actions in cases of moral ignorance.
3. From 1 and 2: if concern for morality de dicto grants moral worth, (nonculpable) moral ignorance excuses.
4. If moral ignorance excuses, it excuses from esteem as well as blame (see Assumptions. Without this, we lose Gideon Rosen’s appeal to “parity” between moral and factual ignorance). In other words: if a person who thinks she’s doing right cannot be blameworthy, a person who thinks she’s doing wrong cannot be esteem-worthy.
5. From 4 and my definition of Huck Finn Case above: if moral ignorance excuses, Huck Finn Cases are not cases of esteem-worthy or morally worthy action.
6. From 1 and 5: if concern for morality de dicto grants moral worth, then Huck Finn cases are not cases of esteem-worthy or morally worthy action.
7. If concern for morality de re grants moral worth, than Huck Finn cases are cases of esteem-worthy or morally worthy action.
8. From 6 and 7: if concern for morality de dicto grants moral worth, concern for morality de re does not grant moral worth.
9. If concern for morality de re grants moral worth, Huck Finn cases are cases of esteem-worthy or morally worthy action,
10. From 6 and 9: If concern for morality de re grants moral worth, Concern for morality de dicto does not.
11. From 8 and 10:
If concern for morality de dicto grants moral worth, concern for morality de re doesn’t, and vice versa.
This is of course compatible with taking either concern for morality de dicto or concern for morality de re to be encouragement worthy, or charming, or good to have around to tide you over when you’re out of the other kind, while holding that (only) the other kind grants moral worth, but I think, again, that there’s an important distinction. (Incidentally, see my previous post to how this relates to Nazis and Bankers).