A belief in free will is akin to
religious beliefs, since neither complies with the laws of the physical world. One of the basic premises of biology and biochemistry is that biological systems are nothing more than a bag of chemicals that obey chemical and physical laws. Generally, we have no problem with the “bag of chemicals” notion when it comes to
bacteria, plants, and similar entities. So why is it so difficult to say the same about humans or other “higher level” species, when we’re all governed by the same laws?
No causal mechanism
As Cashmore explains, the human
brain acts at both the conscious level as well as the unconscious. It’s our consciousness that makes us aware of our actions, giving us the sense that we control them, as well. But even without this awareness, our brains can still induce our bodies to act, and
studies have indicated that consciousness is something that follows unconscious neural activity. Just because we are often aware of multiple paths to take, that doesn’t mean we actually get to choose one of them based on our own free will. As the ancient Greeks asked, by what mechanism would we be choosing? The physical world is made of causes and effects - “nothing comes from nothing” - but free will, by its very definition, has no physical cause. The Roman philosopher and poet Lucretius, in reference to this problem of free will, noted that the Greek philosophers concluded that atoms "randomly swerve" - the likely source of this movement being the numerous Greek gods.