This topic has been buzzing around my mind for a while, so I figure it's time to externalize it. "Free will is an illusion" is a meme that I've seen quite a lot on this site especially. I don't think most people who repeat it have thought much about it.
Yeah, materialism (which I hear is popular around here) suggests a mechanistic universe, one without true randomness, defined solely by predictable input and output. That contradicts our intuition about independent free will, which seems unpredictable (or at least not fully predictable) when we experience it. I don't think a fully mechanistic universe is incompatible with free will, though - in fact, I think that any coherent definition of free will must necessarily exist even under a materialist lens. Those of you who are (like me) pop-philosophy dilettantes probably know that this position is called "compatibilism".
Obviously, though, people disagree. I want to know why. If you don't believe that free will exists, under what circumstances do you think it would exist? What do you think would change if it did exist according to your definition?
I think the problem here is, where do you cram the non physical portion in? Is there an interaction point with the physical?
Either the being with qualia never interacts meaningfully with the object, in which case conscious beings are just floating spirits pretending they make decisions and free will is irrelevant.
Or Qualia interacts with the physical body in some way that a direct simulation does not, producing a different result, in which case we can design an experiment to test where that interaction begins and the needed components for that.