Randomly assign people to a control or experimental condition.
In commonsense morality, can your moral responsibilities to exceed your ability to fulfill them? To test whether this is possible, randomly assign people to evaluate a situation where a man makes a promise that he either can keep (control condition), or cannot keep (experimental condition). Ask people to judge whether the man has a moral responsibility to keep the promise. When the man can’t keep his promise, do people still attribute a moral responsibility?