Palmer defends the ‘Constitution View’ of omissions. According to this view, every omission is constituted by, though not identical to, some positive event. I argue that Palmer’s version of this view can’t do all the work he wants it to do. First, it can’t provide an answer to the ontological question to which he addresses himself: ‘What kind of thing is an omission?’ Second, it doesn’t give us the resources to determine which positive events serve as the ultimate constituters of (...) omissions which seem to occur over long periods of time ; at least, not without embracing consequences Palmer wishes to avoid. (shrink)