[lmm]

I don't think "this belief has negative consequences" is a good argument; we can only reach the truth by sincerely looking for it.

To my mind the very concept of free will is nonsense; as soon as you make a sincere effort to pin it down it breaks down. Yes, there is no absolute proof that it's impossible, but like the second law of thermodynamics, I would be much more surprised to see it violated than, IDK, finding a real magnetic monopole.