Before epilepsy was understood to be a neurological condition, people believed it was caused by the moon, or by phlegm in the brain. They condemned seizures as evidence of witchcraft or demonic possession, and killed or castrated sufferers to prevent them from passing tainted blood to a new generation.
He argues that free will is a myth and we should accept it, but if our choices are predetermined, how do we even choose to accept or reject anything?