How should society change if science shows that human free will is just an illusion?
If we have free will, and someone chooses to make a living by home invasion and robbery, brutally killing anyone unlucky enough to be home at the time rather than leaving potential witnesses behind, society feels both the need and the right to punish such a person. The punishment meted out assumes that they could have acted differently, and consciously chose to ignore their better judgement. We acknowledge that if someone has a mental disorder that renders them incapable of knowing right from wrong, they should be treated differently than a criminal with a normally functioning brain.
For individuals with normally functioning brains, all the major religions condemn home invasions, robbery and murder as highly immoral, sinful, and if left unredeemed, cause for further punishment after death or denial of life in the promised land of Heaven, Nirvana or whatever. But if we learn tomorrow that free will is nothing more than an extremely compelling illusion—if science establishes beyond a reasonable doubt that our brains are nothing more than complex, totally-deterministic computers controlled by the laws of physics and not us—how could man’s law or God’s law reasonably hold us accountable?
What would necessarily change about law, sociology, economics, criminology, morality and religion if we learned that there is no such thing as free will? What if we find that the environment one grows up in, itself shaped by deterministic forces, coupled with the laws of physics; cause out brains to think what they do and we are no more in control of the thought process than we have control of the release of digestive enzymes in our guts? What would stay the same, and what should we change?