[to appear in the Companion to the Philosophy of Action, ed. by T. O’Connor and C. Sandis, Oxford: Wiley-Blackwell] Refraining, Omitting, and Negative Acts KENT BACH Action theory has been primarily concerned with the question of what it is to do something, along with such subsidiary questions as what is to do something intentionally and what it is to do one thing by doing another. It has tended to neglect the question of what it is to fail to do something. As we will see, there are different ways in which one can not merely not do something, but fail to do it. Just consider that at any given moment, including this one, there are countless things you are not doing but very few things (if any) you are failing to do. I bet that at this moment you are not standing on your head or playing a clarinet, much less rescuing someone from a burning skyscraper. Obviously, there is not much point in asking what it is not to do any of the countless things that you could conceivably be doing, and not just because you lack the ability or the opportunity to do most of them. You might not have had the ability to play a clarinet or the opportunity to rescue someone from a burning skyscraper right now, but you could have easily scratched your head or wiggled your right index finger just then. Even though you probably didn’t do either one, you didn’t fail to scratch your head or wiggle your finger, certainly not if you didn’t even consider doing them. On the other hand, now that I’ve mentioned them and implicitly raised the possibility of doing them, the situation is rather different. If you don’t scratch your head or wiggle your right index finger now, you have refrained from doing these things. But change the example. Suppose you intended but have forgotten that you were to call your spouse just about now. Even though you hadn’t considered (until I mentioned it) that you were to have made this call, in which case you can’t be said to have refrained from making it, still you failed to make it. These examples illustrate that there are different ways of failing to do something. A little reflection should reveal that there are least four ways of not only not doing something but of failing to do it: (trying and) not succeeding, refraining, omitting, and (some cases of) allowing. I don’t know if these exhaust the possibilities, but they seem to comprise the main cases, not that they are mutually exclusive. In the following section we will distinguish them and then, in the next two sections, look further at refraining and omitting. We will consider not only what they involve but also whether there can be acts of refraining or omitting. In the final section, we will take up the question of whether in any interesting sense there are negative acts of any sort, that is, acts of not doing something, as opposed to failures to do something.