It seems that for a promise to be sincere, you have to intend to keep it.
But this is false. Suppose you offer to lend me a microscope upon my promise to return it to you when you ask. I know that if I make the promise, then as soon as you ask me for the microscope’s return, your request will remind me of the promise, and I will fulfill it. So, I make the promise. Given that I know I will keep it, I am being sincere. But I don’t need to clutter my mind by forming any intention to keep the promise or to return the microscope.
So perhaps for a promise to be sincere, you need to believe you will keep it.
But this, too, is false. Suppose you’re my accountability partner and I promise to stop drinking, and suppose this is a promise I have broken so many times that I believe that I won’t keep it. But I intend to keep it. And you know my track record, so there is no deception. Again, I think there is no sincerity.
But if sincerity in promising needs neither the intention to keep the promise nor the belief that one will do so, what does it need? Perhaps the disjunction: I need to believe or intend (or, best, both). But normally I prefer to avoid disjunctive accounts.
Let’s think some more and go back to the accountability partner case. If you know my track record, you won’t count on my not drinking. For instance, you aren’t going to vouch for my sobriety to others, you won’t trust me around your liquor cabinet, etc. But suppose you didn’t know my track record. You just heard my promise and counted on it, vouching for me to others, etc. In that case, if I drink, you have two grounds for resentment: that I broke my promise and that I deceived you, leading you to count on good behavior I did not actually expect.
Here is what I think is going on. Normally, when I make you a promise, I do two things:
I obligate myself to you to perform the action, and
I testify to you that I will perform the action.
And I can betray you in either or both respects: I can break my obligation and I can testify falsely.
In the accountability partner case, in the presence of shared knowledge of my track record, the testimony about future behavior that normally comes along with a promise is canceled. In that case, all I do is I obligate myself to you. I expect to break that obligation, but I have good reason to undertake the obligation, namely that the probability that I will stay sober increases (though not enough to justify belief) because I will have an additional reason—my promise to you—to do so. (I think one needs the Principle of Double Effect here. My intended effect is an increased chance of staying sober. The unintended—indeed, counterintended—but foreseen effect is my breaking a promise to you.)
That still doesn’t answer the question of what the sincerity conditions are.
Here is one suggestion. Sincerity only concerns (2), the testimony aspect. In cases where the testimony is canceled, whether explicitly or implicitly (say, in light of shared knowledge), there is no sincerity condition on promising at all. There is only the creation of an obligation.
That doesn’t sound quite right. It seems that if I make a promise to an accountability partner who knows the dismal track record of such promises, I am still being insincere if I don’t intend to keep the promise. But what if the case is really weird, so that I am more likely to keep the promise if I don’t intend to do so when making it? (E.g., maybe I know that there is a neuroscientist who is going to observe my brain and if she detects that I am intending to keep the promise at the moment of making it, she will erase my memory of the promise, while if I don’t intend to keep it, the promise will still come to mind in my moments of temptation and make it less unlikely that I will stay sober.)
Maybe what is going on is this. When the testimony to future performance is canceled, it is normally replaced by an implicit testimony to the intention of future performance (or perhaps an implicature of such an intention?). So in the special case of promises to accountability partners who expect failure, one is deceiving the other party if one lacks the intention to keep the promise. And in the contrived cases where the intention would make it less likely that one would keep the promise, one should take the further step of informing the other party that one is not even intending to keep the promise.
I like the way that this story makes the accountability partner case be different from the standard case of a promise. I also like the modularity on this story. Promises normally have two ingredients, the exercise of a normative power to create an obligation, and testimony to future actions. We already knew that the second ingredient can occur without the first—mere predictions of one’s future actions are like that. It’s rather nice, then, that the first ingredient can also occur without the second.
I don’t know if the above story can be reconciled with the promise account of assertion. If not, so much the worse for the promise account of assertion.