If I am correct, then you are about to read philosophical history. It's a little dense, but it's short, so focus...
This is actually an old philosophy. I cannot remember which old Greek proposed it, but I remember hearing the idea in a philosophy class years ago. It was a dualistic argument against free will asserting that the human mind and body do not actually interract; that they co-exist simultaneously and the mind is tricked into thinking it interracts because it comes to anticipate what the body will do and does not know anything else to anticipate instead. At the time I dismissed the idea as ridiculous because I could not conceive of the logical steps that arrive at that argument, but here I think I have created a proof for the very idea. Admittedly though, it is not an appetizing conclusion for humans, so I would be much obliged if someone could please prove me wrong. Here it is:
1. If reality were only causal (meaning every effect had a cause; every action an equal reaction), then time would be infinite, since any beginning to such a chain would have to be an a-causal event. Time would go only from future to past; cause to effect. Universal laws would exist, determined by fate. They could be observed and predicted, but not interrupted. Choice would not exist.
2. If reality is only a-causal (meaning one effect is not connected to another), then time does not exist (not as the contiguous thing we imagine) and no universal laws, or fate, could exist either. If choice could somehow come to exist, one could never be certain to achieve the result one desires because an a-causal effect would follow any action; an effect not related to the one you had hoped to cause. Or, since events would be unrelated, maybe nothing at all would result from an action.
3. BUT, if reality is causal AND allows for a-causal interruptions, then the universe could have come into being where once it was not, time would exist but not fate, and anything resembling a "law" could be skewed by a-causal interruptions (making their determination relativistic, not universal). I suspect that this is how our reality works, but let us look at what this third possibility means for "choice."
A free choice has to be considered a change to what would otherwise be called "fate;" it would have to be an a-causal interruption in a causal chain of events, then going on to produce effects of its own, which are henceforth related to it causally (until or unless the chain is later interrupted, itself, by an a-causal event). And since a choice has to be an a-causal event, it necessarily CANNOT be caused. It can be observed and its effects suffered or enjoyed, but it cannot be MADE to happen or it cannot be called a-causal. A human is an observer, certainly, but cannot be said to be a chooser, only a sufferer or enjoyer. A-causal things could occur around humans, but should not be called their "choices," any more than the causal things occuring around them should be called their "choices."
Furthermore, even if there were something about humans which could harnessed the paradoxical ability to CAUSE an a-causal event, the results of their using this ability would produce effects entirely unrelated to what they intended to cause. Hence, choice cannot exist: either there is fate, if the universe is deterministic, or there are a-causal events that cannot be consistently predicted or controlled. This means humans are not responsible for anything they do. We are an awareness trapped in a system we cannot effect.