"The prevalence of evil and misery has always bothered those who believe in a benevolent and omnipotent God. Sometimes God is excused by pointing to the need for free will. Milton gives God this argument in Paradise Lost: I formed them free, and free they must remain Till they enthrall themselves: I else must change Their nature, and revoke the high decree Unchangeable, eternal, which ordained Their freedom; they themselves ordained their fall. It seems a bit unfair to my relatives to be murdered in order to provide an opportunity for free will for the Germans, but even putting that aside, how does free will account for cancer? Is it an opportunity of free will for tumors?"