Full Idea
The free will problem is that humans seem to be responsible, but this seems to conflict with the idea that every event is caused by some other event, and it also conflicts with the view that the action is not caused at all.
Gist of Idea
Responsibility seems to conflict with events being either caused or not caused
Source
Roderick Chisholm (Human Freedom and the Self [1964], p.24)
Book Reference
'Free Will', ed/tr. Watson,Gary [OUP 1982], p.24