[Retra]

Free will is basically the feeling of experiencing a mind that operates in a certain way. Just because you don't know what the requirements are doesn't mean it doesn't exist. You could just as well say "love doesn't exist" because physicists don't have a great model of what causes it.

Sure free will exists; it just isn't a objective natural phenomena to be studied under the domain of physics. It's an emotion. It's what happens when you brain builds counterfactual models of its own behavior. It's really no different from things like pride and regret -- you experience them only because you can imagine a reality different from the one you are in. There needn't be any physical mechanism for predicting the construction of those realities.