An argument against conditional accounts of ability
Remember the miners problem. Ten miners are trapped in a mine and threatened by rising water. You don't know if they are in shaft A or shaft B, and you can only block off one of the shafts. Let's not ask about what you ought to do, but about what you can do. Specifically, can you save the ten miners?
According to the simple conditional analysis, you can save the miners iff you would succeed if you tried. So what would happen if you tried to save the miners?
I assume you don't actually try to save the ten miners. You keep both shafts open, knowingly causing the shortest miner to drown. Let's assume that (unbeknown to you) the miners are in shaft A. If you tried to rescue the ten miners, you would arbitrarily choose one of the shafts to block. Let's say you would choose shaft A, simply because you like the letter 'A'. You don't think this is relevant: you don't think the miners are any more likely to be in shaft A than in shaft B. But you have to make your choice somehow. Might as well make it based on your irrelevant preference for the letter 'A'.
According to the simple conditional analysis, it follows that you can save the miners: you would succeed if you tried.
Now consider Bob. He is in an almost identical situation. The only difference is that he likes the letter 'B' more than the letter 'A', so that he would block shaft B if he tried to save the miners. He would fail if he tried.
But do we really want to say that you can save the miners while Bob can't?
I don't have an unequivocal intuition about whether you (or Bob) can save the miners. I think there's a sense in which you can and a sense in which you can't. In Schwarz (2020), I called the first sense 'effective' and the second 'transparent'. According to the analysis I proposed, both you and Bob can effectively save the miners, but neither of you can transparently save the miners. Intuitively, you both can do something – blocking shaft A – that amounts to saving the miners. But neither of you can do something of which you know that it amounts to saving the miners.
The transparent 'can' is the 'can' that is (arguably) implied by 'ought'. It's the 'can' that demarcates an agent's options. If you had the option of saving the ten miners, your choice would be easy: you should choose that option. But your choice isn't easy. Saving the ten miners isn't one of your options. You know that you can do it, but you don't know how. The sense in which you can do it is the effective sense of 'can'.
The conditional analysis tracks neither the effective nor the transparent sense. The problem isn't the specific verdict it gives for you and for Bob. The problem is that it gives different verdicts for the two cases. I don't think there is any useful sense of 'can' in which you can save the miners but Bob can't. Neither of you has saving the miners as an option, and both of you can do something that amounts to saving the miners.
The problem doesn't just affect the simple conditional analysis. It also affects more sophisticated conditional analyses that involve, for example, a high "modal success rate", as in Jaster (2020). I suspect it also affects some non-conditional analyses.
This is an interesting post! I enjoyed reading about this challenge to conditional analyses of ability.
I guess I just wanted to note that it can be pretty intuitive to me what the conditional analysis says in at least similar cases. Imagine I'm watching two people try to solve a (time-limited) maze. I know one is deploying heuristic that is good in many cases but not in this one; the other person uses a heuristic that'll work for them with this maze. It's time-limited, so they really can only try out one sort of heuristic. I think to myself "the first person can't solve the maze, through no fault of their own, but the second person can!". The only difference between them is one is using a heuristic that'll work on that maze, and the other isn't, even though they're let's say otherwise equally likely to be good maze heuristics. The conditional analysis does a pretty good job with this case. Is it different in a way that I can't see from your run-through of the Miners?