THE history of moral philosophy is a history of disagreement, but on one point there has been virtual unanimity: It would be absurd to suggest that we should do what we couldn’t possibly do.
This principle — that “ought” implies “can,” that our moral obligations can’t exceed our abilities — played a central role in the work of Immanuel Kant and has been widely accepted since. Indeed, the idea seems self-evidently true, much as “bachelor” implies “man.”
Suppose that you and a friend are both up for the same job in another city. She interviewed last weekend, and your flight for the interview is this evening. Your car is in the shop, though, so your friend promises to drive you to the airport. But on the way, her car breaks down — the gas tank is leaking — so you miss your flight and don’t get the job.
Would it make any sense to tell your friend, stranded at the side of the road, that she ought to drive you to the airport? The answer seems to be an obvious no (after all, she can’t drive you), and most philosophers treat this as all the confirmation they need for the principle.
Suppose, however, that the situation is slightly different. What if your friend intentionally punctures her own gas tank to make sure that you miss the flight and she gets the job? In this case, it makes perfect sense to insist that your friend still has an obligation to drive you to the airport. In other words, we might indeed say that someone ought to do what she can’t — if we’re blaming her….
“Ought” judgments depended largely on concerns about blame, not ability. With stories like the one above, in which a friend intentionally sabotages you, 60 percent of our participants said that the obligation still held — your friend still ought to drive you to the airport. But with stories in which the inability to help was accidental, the obligation all but disappeared. Now, only 31 percent of our participants said your friend still ought to drive you.
Professor Sinnott-Armstrong’s unorthodox intuition turns out to be shared by hundreds of nonphilosophers. So who is right? The vast majority of philosophers, or our participants?…
Even when we say that someone has no obligation to keep a promise (as with your friend whose car accidentally breaks down), it seems we’re saying it not because she’s unable to do it, but because we don’t want to unfairly blame her for not keeping it. Again, concerns about blame, not about ability, dictate how we understand obligation.
So here we face the other possibility, one less flattering to most moral philosophers: It’s their moral judgments that are distorted.
In the last decade or so, the “experimental philosophy” movement has argued for greater use of empirical science to inform and shape the discussion of philosophical problems. We agree: Philosophers ought to pay more attention to their colleagues in the psychology department (even if they can’t).
From The NYTimes
While this one study alone doesn’t refute Kant, our research joins a recent salvo of experimentalwork targeting the principle that “ought” implies “can.” At the very least, philosophers can no longer treat this principle as obviously true.
It is often thought that judgments about what we ought to do are limited by judgments about what we can do, or that “ought implies can.” We conducted eight experiments to test the link between a range of moral requirements and abilities in ordinary moral evaluations. Together these results demonstrate that commonsense morality rejects the “ought implies can” principle for moral requirements, and that judgments about moral obligation are made independently of considerations about ability. By contrast, judgments of blame were highly sensitive to considerations about ability (Experiment 8), which suggests that commonsense morality might accept a “blame implies can” principle.