> Newtonianism doesn't seem relevant to my question. It is a random event if you're not trying to make it not-random. I could just say the word "heads" and cont

> Newtonianism doesn't seem relevant to my question. It is a random event if you're not trying to make it not-random. I could just say the word "heads" and continue with my day based on the "heads" decision if I wanted to affect the outcome. If we're discussing whether the future is fully determined by the past, this point is rather important. In a fully classical (newtonian) world, the future is fully determined by the past - so the result of that coin flip was already determined not just at the moment the coin was thrown, but in fact the moment the universe began. Now, with QM, whether this remains true or not is much more debatable. In the many-worlds interpretation for example, it does remain true: in that interpretation, the whole universe evolves according to the Schrodinger equation, with all possible outcomes of a quantum measurement actually happening, just not in the same place in phase space. In the more common interpretations, there is true randomness, with only one outcome happening from a random event and no way to predict which it will be. So, in the most common interpretations of QM, while coinflips may not be very random, you could instead measure the spin of an electron and base your decisions on that, and no one could predict the future if you do so. Still, note that you are not choosing anything, in either interpretation. Your next action is as unpredictable to you as it is to anyone else, if there is true randomness. Your thoughts, beliefs, experiences, do not influence your actions in any way if you base your actions on a random event. So, if you believe that a deterministic universe is not compatible with true free will, then you should also believe that a random universe is just as incompatible with true free will.