The test whether a choice causes something is to see whether if I did not exist or could not act (e.g. was unconscious), the thing would not occur.
In the given example, if I poison someone I cause his death, since if I could not act for whatever reason there would be no poison. But if someone is drowning without my doing and I just happen to come along and choose not to throw a life belt I would not be causing his death since he would drown anyway if I could not act.
The test whether a choice causes something is to see whether if I did not exist or could not act (e.g. was unconscious), the thing would not occur.
In the given example, if I poison someone I cause his death, since if I could not act for whatever reason there would be no poison. But if someone is drowning without my doing and I just happen to come along and choose not to throw a life belt I would not be causing his death since he would drown anyway if I could not act.
Ah, I see. OK, I understand you now. Thanks for clarifying.