There is plenty of interesting science demonstrating that we choose, subconsciously, fractions of a second before we are consciously aware of the choice. And yet, test subjects are adamant, they freely, consciously choose.
These results are interesting, but are not, to my mind, necessary to dispose of free will; the concept itself is logically unsound.
Consider the problem philosophically. Ask yourself why you would choose one choice over another? Keep it mundane: fish or pasta for dinner. Look closely enough and there will be a reason. You feel like fish. You had pasta last night. What is the reason? Now ask yourself, why would that reason decide the matter? Why would it matter that you had pasta the night before? Is it because you are a person who likes culinary diversity? Have you decided pasta is not healthy two nights in succession? Are you watching your starch intake? Regardless of the answer, you are guaranteed to settle upon a reason.
So, you are the type of person who decides by reason. Why are you that type of person? Why do reasons matter to you? (Could it be because you are part of the universe? And to act in any way requires a cause? Yes, even the statement ‘because I felt like fish’ is a reason; feeling is causal). Did you choose to be a reasonable person? Did you choose to feel that way? And if the answer is yes, why did you choose to be reasonable, why did you choose to feel that way? What would it be like to exist and to act without reasons and feelings? Is that even possible? (I think the answer is clear).
And let us suppose you are unreasonable. Let us say you actually take great pleasure in being absurd. You do everything contrary to good sense and what your gut tells you. Is that freedom? Wouldn’t identifying the opposite of good sense be the first step, and once you have identified that you proceed accordingly? Haven’t you just substitute a good cause for a contrary cause? Aren’t they both causes? Have you actually found freedom here?
Or suppose you really have no preference. Let us admit that the choice between fish and pasta is truly a stochastic one, a flip of the coin. You need to eat, so the question of freedom does not live or die with the need to eat, but with the choice of food. Yet. if you choose by the flip of the coin, where is the freedom in that? In the absence of any preference, any reason, you leave the choice to fate. Your choice is no longer a choice.
‘Choice’, or better, the illusion of choice, depends on the state of your brain before a choice is taken. What are the impossibly complicated environmental, cultural, genetic causes that set your brain in that state before the choice? Did you freely choose each of those states? (As if that were possible). For each one of your behaviours, your choices, there is a cause, a reason, you were not free to choose. That is because each of those causes and reasons had, in turn, a cause and reason for their existence. Take this truth and work step-wise backwards to the womb, and you can only conclude the person you are and the reasons you decide upon to act are the result of causes completely beyond your freedom to choose. And not only your freedom, but the freedom of your mother, of your father, of your grandparents, of their parents, of the common ancestor of chimps and humans, of the common ancestor of mammals, of its ancestor to all animals, of the organisms straddling the eukaryotic and prokaryotic divergence, of the first self-replicating molecules, the precursors to life, of the molecules composed of the elements from the exploding stars of the galaxy, of the galaxy, of the universe, of the freedom of existence itself.
Logically, the concept of free will makes no sense.