Plausibility and Argument
For any argument to work, paraphrasing economist Bryan Caplan, the plausibility of its premises must be greater than that of the denial of its conclusion. Caplan continues: Since no premise has greater initial plausibility than "This is a hand," said [philosopher G. E.] Moore, it is in principle impossible for that claim to be overturned." I think that the same is true of the existence of free will. Nothing has greater initial plausibility than the premise "I have free will"; no scientific or philosophical argument will ever have greater initial plausibility. So how is it even coherent to argue against free will? Any valid argument showing that free will does not exist serves merely as a reductio ad absurdum of that argument's premises, not a disproof of the freedom of the will.