The following was part of an argument I presented over at Thinking Christian.
Intuition tells us that, from our perspective, we affect future events by examining the choices of action before us, simulating the outcome of each action, choosing the preferred outcome, and executing the chosen action. That's decision-making.
Furthermore, it is intuitive that making a decision often leads to different results than making no decision.
That is, from our perspective, our decisions (or lack thereof) affect the future. That's what intuition tells us. Intution cannot tell us that the universe is non-mechanistic because our intuition is not sensitive to that factor.
If the universe is mechanistic, our decisions still affect the future as seen from our perspective. Our experiences are totally insensitive to the question of, say, whether or not our actions could have been predicted a million years ago.
Suppose that I have weighed my dinner options against my preferences, and decided to eat a hamburger at Wendy's. Suppose that I then learn (never mind how) that the universe is totally mechanistic. Does this mean that I no longer have to act to obtain my Wendy's hamburger? If I do nothing, will the burger come to me as if by magic? Of course not. My decisions still affect the future from my perspective, even if they are not affected from an omniscient point of view. I still have to decide which dinner option I prefer, and execute my tasks in order to get my dinner. If I choose to do nothing, then, presumably, I was predestined to do nothing. If I choose to cross the street and go to Burger King, then I was destined to go to Burger King. The fact always remains that I choose my destiny.
The same would be true if I had magically found out that the universe was not mechanistic. I would act in exactly the same way.
So, from a human perspective, the mechanistic nature of the universe makes not a jot of difference to will, choice and action.
This is why the mythical association between free will and a lack of determinism is just a confusion. If anything, will and rationality rely on determinism.
If one defines free will to be equivalent to a lack of determinism, then one is begging the question. One would be defining free will to be supernatural or perhaps even illogical. Determinism and randomness are logical complements, and there's no third choice which logically delivers the kind of options that supernaturalists seek.