Doing Good and Doing the Best

It is sometimes argued that, even when it is supererogatory to give to charity at all, once one has decided to give a certain amount, one is then required to give in the way one has reason to believe will do the most good, or prevent the most harm, among the options of which one is aware. This chapter argues that once one has incurred the cost of preventing some harm and one then has a choice between preventing a greater harm and preventing a lesser harm, one is required to prevent the greater harm, if other relevant considerations are equal. But if one has not yet incurred any cost and one can prevent a greater harm or a lesser harm, each at the same cost, it is in general permissible to prevent the lesser harm. Most instances of charitable giving are of the latter sort.