What William Miller teaches us is that a change of heart can’t be imposed; it can only be chosen. People are capable of making enormous sacrifices when they have the agency to act on their own. For instance, healthcare professionals have known for decades that if you give patients control of their own IV-administered painkillers, they’ll use less than when the painkillers are provided by a nurse. Give people a choice, and they’ll step up to the plate. On the other hand, they’ll resist compulsion on pain of death. Try to keep drugs from them, and they’ll demand more.
