> but what most people think it means is that if time were wound back and replaced, a person could have made a different choice than they previously made.
I disagree and I think the paper I linked literally proves that people do not think this way. Per the paper, most people agreed with "source Compatibilism", where people considered an agent responsible if they were the ultimate source of the choice. I recommend reading the paper, it's well done and very accessible.
> In what way were you free to choose one and not another? I contend that you are not free to choose what thoughts pop into your head. Where is free will then?
The freedom to choose according to your desires. The fact that you don't have a choice in your desires doesn't seem relevant.
Think about it mechanistically: suppose you have a machine learning model that can act as an intelligent agent, and this model responds to moral feedback, eg. you tell it when it did something morally wrong or right, and it updates its internal state to reflect what it's learned and makes better choices in the future. It's capable of abstraction and generalization in order to learn general moral principles rather than merely memorizing specific rules.
After some period of training, doesn't it seem reasonable that you could trust such an agent to make ethical choices, no matter what its initial state was? Even if you initialized it with maximal hostile intentions, but it still operated basically the same as one initialized with maximal altruistic intentions, they would both converge roughly to similar points on important moral questions.
Maybe the hostile one might be a little more selfish in circumstances of moral ambiguity where the other will still err on the altruistic side, but I would argue you can still mostly trust it to make ethical decisions.
Such agents still probably won't be perfect, and where they mess up we would require more ethical feedback to update its internal state that drives its decision procedures.
What is this feedback loop if not holding the agent morally responsible for its choices? How are humans any different from such mechanistic agents? As children we know little but have certain proclivities towards selfishness or charity, and adults teach us when we've done something right or wrong, and we internalize and generalize that kind of logic as we mature. We don't have a perfect system for determining when someone is fully mature and ready to make ethical choices, but the heuristic of 18-21 years old seems to generally work.
The initialization state doesn't seem particularly relevant. Maybe the hostile agent prefers ice cream where the altruistic agent prefers chocolate bars, but this isn't really relevant to whether they are free to make choices according to their internal reasons, and whether they respond to being held morally responsible for poor choices.
The only freedom worth having is the type that lets you choose according to what you value, and that turns out to be the kind of freedom we do have.