- (Premise) Any circumstances that are sufficient to determine a person with a character free of moral failings to do wrong are exculpatory for such a person.
- (Premise) There was a first wrongdoing and it was not done in exculpatory circumstances.
- So, either the first wrongdoer was not determined by circumstances and character, or the first wrongdoer had antecedent moral failings. (1 and 2)
- (Premise) the first sinner did not have antecedent moral failings.
- So, the first wrongdoer was not determined by circumstances and character. (1 and 4)
Premise (2) seems to be a part of the standard Christian picture. Nobody thinks Satan first sinned in circumstances that are exculpatory. Premise (4) follows from the fact that moral failings are evils, and evils came from sin (in the full sense of a wrongdoing the agent is responsible for—"formal" sin in Catholic terminology).
That leaves (1). But consider this line of thought. Suppose I was tortured and under torture I turned in my friends. Am I responsible or has the torture taken away my responsibility? Here is a test. I imagine whether a person free of moral failings would have been determined to do the same under torture of this intensity. If so, then the torture is of sufficient intensity to be exculpatory for me, and presumably likewise for her. (It doesn't quite follow that I am exculpated. For I could still be responsible for my sin in exculpatory circumstances, if my action is overdetermined by the exculpatory circumstances and something I am responsible for.)