Full Idea
The Stoics said that everything happens according to a divine providential plan, so they had to explain how this was compatible with human choices. They tried to do this with their doctrine of freedom and a free will.
Gist of Idea
The Stoics needed free will, to allow human choices in a divinely providential cosmos
Source
Michael Frede (A Free Will [1997], 10)
Book Reference
Frede,Michael: 'A Free Will' [Univ of California 2011], p.176
A Reaction
Epictetus made our ability to choose central to moral life, so he particularly needed (and thus created, it seems) this doctrine.
Related Idea
Idea 23328 The essences of good and evil are in dispositions to choose [Epictetus]