Huxley (Darwin’s bulldog) – The physical world has causal closure. Physical things are caused by physical things. The biological brain is part of that physical world. IF the mind is not physical, then it cannot cause physical things to happen, and must just be a by-product, and epi-phenomenon, of the physical. Mind and mental things are just the “hum” of the brain machine, not the cause of anything.
Yeah, close. Of course the theological response is that divine intervention closes the causality between the spiritual and the physical. The real problem is the word IF. Better conclusion is that mind, free-will, intention, etc are also physical. Where’s the problem ?