I'm not aware of anyone making the argument that without free will knowledge does not exist.
And really the situation is simple. Either you believe in determinism or you believe in libertarian free will. The problem is that one of these beliefs is supported by science and the other requires magic.
And really the situation is simple. Either you believe in determinism or you believe in libertarian free will. The problem is that one of these beliefs is supported by science and the other requires magic.