Faust: Quantum physics is incomplete and I'm sure there are hidden variables.
EI: I really can't argue with faith. I just don't have it.
Let's say you are watching a conjurer's trick and he seemingly produces a rabbit out of thin air. Your companion turns to you and says, "Look at that! It's magic!"
Since you are a man of truth, you might reply, "No, it is merely a trick. There is sure to to be a mundane explanation for it."
Your companion: "But look at the evidence before you! He just produced the rabbit out of nothing! How can you argue with that?"
You: "There are bound to be hidden factors involved".
Your companion: "I didn't see any of these so-called 'hidden factors'. I'm sorry, but your theory sounds a bit flimsy to me."
You: "Your picture of what occurred is incomplete."
Your companion: "Well, I really can't argue with faith. I just don't have it."
Sound convincing to you?
The philosopher Popper suggested that anything that isn't falsifiable isn't within the realm of science. We can always insist that something that appears random has hidden factors at play, and if we are to do so, then we render universal determinate causality a dogma that can never be proven wrong. Thus, we should say, that such a notion isn't testable, and any evidence you claim to have for such a thing is worthless.
The trouble is, determinism is a philosophical principle, not a scientific one. It is indeed testable, not through empirical evidence, but through the exercise of pure logic.
It should make a difference. If the world was indeed entirely random, then it would mean that your own thoughts and decisions would also be entirely random, which would undermine the very concept of "will" from the outset. In a random world, there wouldn't be any mechanism for will, let alone free-will.The second type of freewill is compatibilist freewill, whereas its believed absurd to think that decisions aren't determined by physical reality, but that such a fact doesn't change anything about their phenomenal reality. To a compatibilist it makes no difference if the world were entirely random or entirely determined.
From Wisdom of the Infinite:
-Where Does Our Will Begin?
The question of free will is first and foremost a question of origins. Do our thoughts and decisions originate in our brains (or minds)? Or are they like everything else in the Universe and have innumerable antecedent causes which stretch back into the beginningless past? The answer to this is crucial to the resolution of the question of whether free will exists. For if our thoughts and decisions have no ultimate origination, then free will cannot ultimately exist.
We can go further. Even if we assume, for the sake of argument, that origins are possible, be it in the brain or wherever, it would still be impossible for free will to exist. An event that originates without cause is, by definition, a completely spontaneous and random event, which is totally incompatible with the concept of free will. Decisions that mysteriously pop into our brains without rhyme or reason cannot be classed as an act of will on our parts. They are no more a product of our will than is the toss of a coin, or the random generation of lottery numbers.
Here lies the essential irony of free will. On the one hand, free will, as a process, needs the existence of causality in order for it to function. It needs causality because free will is a concept that refers to the mind willing or causing things to happen. And yet, at the same time, it is the sheer reality of causality which nullifies its existence. Thus, the very conditions which are needed to support it are also the very conditions which erode all possibility of it existing. It therefore cannot exist.