Interesting quote about the Stoic idea of fate:
Chrysippus employs the example of a cylinder made to roll down a hill (Cicero, On fate 42–3 = Long and Sedley 1987, 62C 8–9; Aulus Gellius, Attic nights 7.2.11 = Long and Sedley 1987, 62D 4). He says that there are two distinct types of cause working here. One is our pushing the cylinder to make it move; this is the ‘auxiliary and proximate cause’ – we can call it the ‘external cause’. And the other is the cylinder’s being round; this is the ‘complete and primary cause’ – which we can call the ‘internal cause’ (see Long and Sedley 1987, 62C 5–6). We may be inclined to object that the being round is not really a cause. It is a property that the cylinder has, as would be its redness and heaviness, just in case it is red and heavy. Chrysippus could reply, and say that whereas the colour and weight of the cylinder have no bearing on its rolling – a blue, light cylinder rolls just as well – its roundness does have a bearing on its rolling: if it weren’t round, it wouldn’t roll. We would say that the roundness was a necessary condition for the cylinder’s rolling, just as the pushing of the cylinder was also necessary: no push, no rolling. But together both the roundness and the pushing were sufficient for the rolling. Chrysippus wants us to note that both the external cause and the internal cause themselves had causes properly located in the causal nexus comprising the entire history of the world. The external cause of the push was itself caused by our foot swinging to meet the cylinder, and the internal cause of the cylinder’s roundness was caused by the manufacturing process that made it. And we may suppose that the rolling will itself cause something else to happen, such as the knocking over of a sheep, or a splash in the stream, or both. In short, nothing has happened which violates the theory of causal determinism.