I once read that a good part of the situation in which we find ourselves today, is due to the decisions we made earlier, so, although there is no "simple and unique cause" for each thing, it can happen that the sum of multiple effects give us the result we have, is the same as saying that the "reality" we live can be commonly poly-causal.

That fits quite well with the idea that while the world gives you conditions to decide (although sometimes they are limited conditions), the decisions you decide to make and the consequences they carry always fall on your will.