 Let us conclude this survey of the physical part of Stoic philosophy with the question of causal determinism, though this is an issue that will emerge again in the following section on logic. The clear first impression of Stoic philosophy is that they are determinists about causation, who regard the present as fully determined by past events, but who nonetheless want to preserve scope for moral responsibility by defending a version of compatibilism. That characterisation is not wrong exactly, but it makes the matter sound far simpler than it in fact is since it effaces some important differences between our framework for discussing these matters and that of ancient philosophers. One key difference is that most contemporary thinking about causation treats it as a relation between events. But ancient discussions of causation take place in a context that has no ready vocabulary for events. That doesn’t mean they denied the existence of events or failed to notice that things happen. It just means that there is no specific piece of philosophical terminology for contrasting what happens with the things that it happens to or with truths about what happened. When we speak of events, we speak of things that helpfully fill the gap between things and statements. Since they take place at a particular time and involve some objects and not others, events are somewhat thing-like. (Even theories of events that don’t treat them as concrete particulars must in some way do justice to this aspect of event talk.) On the other hand, they also have a propositional structure of sorts. The event of Seneca sitting in a bathtub contemplating a book involves such objects as Seneca, his book and his tub, but it involves them in a way that has a kind of structure. Though it involves the same objects, the event of Seneca sitting on his book and contemplating his bathtub is very different from the first event. Absent a robust concept of causation as a relation among events, Stoic analyses of causation sound very odd to the modern ear.