Suppose Bill is a healthy man without family or loved ones. Would it be ok painlessly to kill him if his organs would save five people, one of whom needs a heart, another a kidney, and so on? If not, why not?
Consider another case: you and six others are kidnapped, and the kidnapper somehow persuades you that if you shoot dead one of the other hostages, he will set the remaining five free, whereas if you do not, he will shoot all six. (Either way, he'll release you.)
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