If they steal a car because someone has a gun to they or their spouse's head: Not responsible
Why: Because the causal chain of events that have gotten us to modern humanity have resulted in our cognitive functions valuing human life over physical objects. These are the inputs to the system. These are all causal, products of evolution, etc, and deterministic. The output, the lack of moral responsibility when it's a matter of a human life, is just as causal and deterministic. Free will is not a requirement to come to these conclusions.
If we had evolved in such a way that we kill and eat our spouses after mating like some other species on Earth, but vehicles were a scarce and irreplaceable resource, our morality would be quite different and the thief would likely be morally responsible in both cases. (For what it's worth, I much prefer that we do not live in such a reality ;))
> If they just steal a car: Responsible
>
> If they steal a car because someone has a gun to they or their spouse's head: Not responsible
>
> Why: Because the causal chain of events that have gotten us to modern humanity have resulted in our cognitive functions valuing human life over physical objects
Our values have little to do with the question of free will. A value system determines what we consider to be good or bad, it does not determine who is responsible for a specific good or bad outcome.
So if the thief is not responsible for stealing the car in the hostage scenario, then I assume that you agree that the hostage taker is responsible. And the reason you reach this conclusion is because you assign moral agency to the thief when he's acting alone, and you acknowledge that he has no moral agency when he's being coerced. In other words, he's acting of his own free will in one circumstance, but not the other.
Simply saying "we value life over property" does not enable you to absolve the thief for his immoral act.
If they steal a car because someone has a gun to they or their spouse's head: Not responsible
Why: Because the causal chain of events that have gotten us to modern humanity have resulted in our cognitive functions valuing human life over physical objects. These are the inputs to the system. These are all causal, products of evolution, etc, and deterministic. The output, the lack of moral responsibility when it's a matter of a human life, is just as causal and deterministic. Free will is not a requirement to come to these conclusions.
If we had evolved in such a way that we kill and eat our spouses after mating like some other species on Earth, but vehicles were a scarce and irreplaceable resource, our morality would be quite different and the thief would likely be morally responsible in both cases. (For what it's worth, I much prefer that we do not live in such a reality ;))