When moral philosophers study ignorance, their efforts are almost exclusively confined to its exculpatory and blameworthy aspects. Unfortunately, though, this trend overlooks that certain kinds of propositional ignorance, namely of the personal costs and benefits of altruistic actions, can indirectly incentivize those actions. Humans require cooperation from others to survive, and that can be facilitated by a good reputation. One avenue to a good reputation is helping others, sticking to moral principles, and so forth, without calculating the personal costs of (...) doing so, e.g., saving someone from a burning building without calculating how personally costly or beneficial it would be. These actions are indirect moral benefits (partly) resulting from that kind of propositional ignorance. (shrink)