 Austin holds that modifiers like “voluntarily” and “involuntarily” are used to assert the respective presence and absence of specific elements in the general machinery of action. (He suggests that such apparent pairs do not invariably target the very same specific elements. See 1957: 189–193.) Austin thinks that philosophers have tended to assume that, given that someone has done a specific thing, it will always be a further question whether those pieces of machinery are present or absent. Moreover, philosophers have aligned that question with the question whether the actor was responsible for what they did or acted freely. Those philosophers have in effect been making the following pair of assumptions. They’ve assumed, first, that there is a single type of piece of machinery such that for any action, the action will be free and responsible just in case it involves that machinery. Second, they’ve assumed that the various aggravations serve indiscriminately to mark the presence of the required type of machinery, while the various excuses serve to mark its absence.