It is not enough to ask, ‘Will my act harm other people?’ Even if the answer is No, my act may still be wrong, because of its effects on other people. I should ask, ‘Will my act be one of a set of acts that will together harm other people?’ The answer may be Yes. And the harm to others may be great. If this is so, I may be acting very wrongly, like the Harmless Torturers.

It is not enough to ask, ‘Will my act harm other people?’ Even if the answer is No, my act may still be wrong, because of its effects on other people. I should ask, ‘Will my act be one of a set of acts that will together harm other people?’ The answer may be Yes. And the harm to others may be great. If this is so, I may be acting very wrongly, like the Harmless Torturers.

Derek Parfit