Determinism and free will completely contradict each other and cannot be both true simultaneously.

As it seems from Nail_Bat's argument we are arguing about the definition of "Determinism" and "Free Will". Let's start with several formal definitions of "Determinism": "The philosophical doctrine that every state of affairs, including every human event, act, and decision is the inevitable consequence of antecedent states of affairs." (dictionary.com) "In philosophy, theory that all events, including moral choices, are completely determined by previously existing causes that preclude free will and the possibility that humans could have acted otherwise. The theory holds that the universe is utterly rational because complete knowledge of any given situation assures that unerring knowledge of its future is also possible." (britannica.com) "A theory or doctrine that acts of the will, occurrences in nature, or social or psychological phenomena are causally determined by preceding events or natural laws" (merriam-webster.com) It is clear to see that the common denominator of all three definitions is that every state of affairs is the inevitable consequence of some previous antecedent states of affairs. It does mean that we live in a clockwork world. You ask – "What if we turned the clocks back and let the universe run again? Would it turn out the same as it is now?" A determinist will answer your questions and say – if we could turn the clocks back and let the universe run again it will turn out the same way as it now. Next, we should consider the Heisenberg Uncertainty Principle. If we accept it as it was understood by Heisenberg, we must accept uncertainty as a property of the world itself. This contradicts determinism (inherently by its definition), and as expected, its detractors who believe in underlying determinism (the Copenhagen interpretation), claim that there is no fundamental reality the quantum state describes, just a prescription for calculating experimental results. There is no way to say what the state of a system fundamentally is; only what the result of observations might be. It has to be said clearly – any claim for uncertainty in the world itself contradicts determinism, as nothing is inevitable. Even saying that Heisenberg Uncertainty Principle presents only an infinitesimally small chance that things would not happen as they should (in the strong sense of the word), approves the existence of uncertainty as a property of the world itself, and contradicts determinism. … Regarding free will we'll also consider some formal definitions: "The power of making free choices that are unconstrained by external circumstances or by an agency such as fate or divine will." (thefreedictionary.com) "The doctrine that the conduct of human beings expresses personal choice and is not simply determined by physical or divine forces." (dictionary.com) "Freedom of humans to make choices that are not determined by prior causes or by divine intervention" (merriam-webster.com) "In humans, the power or capacity to choose among alternatives or to act in certain situations independently of natural, social, or divine restraints." (britannica.com) I'll put in these words: any claim for free will must approve that humans have a high metaphysical freedom that allows them to choose between alternatives - the power or ability of agents to act otherwise than they in fact do. You say - "I don't know about you, but I've never been able to act in a way that I didn't act" – however, if you couldn't choose to act otherwise than the way you've acted, in what terms can we say that your decision was "free"? … The main problem with your cognitive-physical peace is that it relies on human abilities to perceive and understand the real world and not concern with the world itself. You describe the cognitive standpoint as a practical standpoint, saying "we will never be able to have enough information, or enough time, to process all of the physical interactions going on in the brain during any decision", while doctrines like determinism and free will claiming for the existence of some property (causativeness in determinism and metaphysical freedom in free will) in an objective reality, independent of humans subjective perception. Determinism and free will may turn out wrong if causativeness or metaphysical freedom are only illusions. You take a skeptic standpoint and say that we as humans will never be able to say if the world is deterministic or not , however the fact that we can't decide which doctrine is true and which is false doesn't mean that they're both true (or both false). Furthermore, let me remind you that I'm not arguing whether there is a way to proof one of those two doctrines or not, but that they're completely contradict each other by definition and cannot be both true. I'll suggest that in your next arguments, you'll explain how these two opposites can settle down without distorting their definitions. What is the significance of saying that determinism and free will do settle down, if determinism is not deterministic and the free will is not free?