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?
Did you read the third paragraph of my first reply? I already addressed the acausal mind idea. It's untenable - either it would be indistinguishable from a purely causal mind, or it would make decisions randomly (which sort of defeats the point of free will).
And sure, mosquitoes have free will. So do trees, mushrooms, and bacteria. To a much lesser extent than humans (their decision space is way more constrained), but it's there.
I think then our only disagreement is actually nomenclature honestly