 As early as 1982 Derek Parfit raised the following question: imagine that you can save the right arm of another person at a great cost to yourself; but if you decide to do so, you can save also his left arm at no extra cost to you; are you under a duty to save both arms? Parfit’s answer is the intuitive one: yes, you ought to do so (Parfit 1982, pp. 131-2). Yet this answer does not easily fit theories of supererogation according to which if saving one arm is supererogatory, saving two arms must a fortiori be supererogatory. This question gave rise to more recent debates about "Effective Altruism". The idea is that even if there is no duty to give to charity, it is wrong to give to a charity which is ineffective; or in other words, once the bounds of duty are crossed and one’s action is supererogatory, it ought to be optimal, especially if the extra costs and risks are only marginal or non-existent (Pummer 2016). If two children are stranded in a burning house and you risk your life by entering the house and save one child, you ought to save also the other child if that does not incur further risk to you. The two children have no claim on you as long as you stand outside just doing what your duty demands (calling the fire fighters); but once you are inside, the second child has a claim on you to be saved too. The same justification not to save a child from a burning house (the extreme risk) must apply to both children. But once you are inside the house and have already risked your life, this justification does not work if you choose not to save the other (Horton 2017). Against this demand for optimization (limited only by agent-relative qualifications) there is the unqualified, non-consequentialist argument that one needs no excuse or exemption from avoiding entering the burning house and that optimization is not a duty. Thus neither the two children together, nor the second child separately, have a claim against the bystander for not acting in the optimal way (Sinclair 2018). Although for the non-consequentialist there is no duty of optimization of the good, he or she admits that once one gave up the justification for not entering the burning house, one cannot use the risk in order to avoid saving the second child because the risk has already been undertaken in saving the first child (Sinclair 2018).