I’m thinking about something.
I do not see why hard determinism would be incompatible with agent causation and free will.
Hard determinism: Exact knwoledge of all states of affairs at one point, would make it possible to predict all future states of affairs with 100% accuracy. For this post let’s assume that agent causation is possible, so that agents can be one ultimate source of change in the universe and have the ability to freely choose.
People intuitively think, that if all states of the universe are entirely determined by laws of nature, agent causation could not exist. I share this intuition, but I disagree rationally. At least logically those two concept are not incompatible.
It is logically possible when we find at least one theoretical way in which both concepts can be true at the same time. And this way exist:
If agent causation influences directly or indirectly the laws of nature to bring about the agents decision, than the agent would truly choose and the universe would truly be (hardly) determined.
I say directly or indirectly because it is not even necesary that the agent has the power to change the laws of nature. It would also be possible that there is an entity that has the knowledge of our future/potential decisions and brings those about by tuning the laws of nature in a way, that will bring about our decisions.
I know that this options seems weird. But it should not be dismissed, just because it sounds strange. Quantum physics sounds strange, but still happens.
I am neither arguing for determinism nor for free will here. I am just stating that even hard determinism would still be compatible with free will. Even if we could predict the behavior of persons with 100% accuracy, that still would not mean, that they did not choose freely.
Therefore free will can never be challenged empirically and has do be debunked philosophicaly.