 The propositional event-like structure of the effect in the Stoic account of causation is given by the insistence that the cause brings it about that a body has a predicate true of it. But if we think about Sextus’ example, it’s not just the scalpel that is the cause of the flesh being cut, for it did not cause this when it was stored safely in a drawer. So there’s event-like structure (the flesh’s being cut) on the effect side of the causal interaction in the Stoic analysis, but not on the cause side. There we have just the body, the scalpel. The role of the event-like structure of the cause in the Stoic scheme is fulfilled by talking about a whole range of different kinds of causes. The sources on the Stoic taxonomy of causes are complex and conflicting, so we can confine our attention to a few of the more important kinds: preliminary causes, sustaining causes, and proximate causes. In this respect, the Stoic view is not wholly unlike Aristotle’s account which famously included ‘the four causes’. It would be more accurate to say that Aristotle’s four causes are four kinds of explanatory factors. What Aristotle does not say, however, is that the presence of these explanatory factors necessitates that which they explain. Causal processes involve a kind of generality for Aristotle. They bring about these things ‘always or for the most part’ but that is very different from the Stoic insistence that causes necessitate. The working out of the divine plan by God or the world’s pneuma they call ‘fate’ and describe it as a sequence of causes that is ‘inescapable’ (aparabatos Aetius, 55J; cf. Gellius, 55K). In On Fate Cicero sought to explain how Chrysippus attempted to avoid the conclusion that, since our actions come about by prior causes, they are not in our power. Chrysippus’ answer turns on the different kinds of causes the Stoics sought to identify and it is worth quoting at length: