Here's my theory on 'freewill'/'choice'.....how does it stack up? :)?

Everything is governed by the laws of 'cause and effect', down to the last atom, since nothing in the universe is truly random, not even radiation. Since all our brains are are neurons and electrical signals etc, they are too governed by the same laws as everything else and therefore their ‘actions’ by the causes and events that have previously occurred. Or in other words they are governed by cause and effect. This thus means that there cannot be freewill and the a belief in freewill will be a belief in the supernatural. Similarly a belief that choice exists will be a belief in the supernatural.