Do the conditions for moral responsibility differ according to whether what is at issue is an action or an omission? John Fischer and Mark Ravizza claim that they do. In their opinion, someone may be morally responsible for performing an action even though he could not have done otherwise; but a person cannot be morally responsible for omitting to perform or failing to perform an action if he could not have done otherwise – that is, if he could not have performed it. The idea that there is an important asymmetry of this sort between actions and omissions strikes me as rather implausible. There appears to be no fundamental reason why instances of performing actions should be, as such, morally different from instances of not performing them. After all, the distinction between actions and omissions is not a very deep one. Indeed, it is often a rather arbitrary matter whether what a person does is described as performing an action or as omitting to perform one. So it would be surprising if the moral evaluation of actions and of omissions differed in any particularly significant way.

Imagine that a person – call him “Stanley” – deliberately keeps himself very still. He refrains, for some reason, from moving his body at all. Why should our moral evaluation of this situation require attention to considerations – having to do with whether Stanley was free to behave differently – that would have required no attention whatever if we were evaluating a situation in which he deliberately made his body move?