In his article “Utility Cascades”, Max Khan Hayward argues that act-utilitarians should sometimes either ignore evidence about the effectiveness of their actions or fail to apportion their support to an action's effectiveness. His conclusions are said to have particular significance for the effective altruism movement, which centers seeking and being guided by evidence. Hayward's argument is that act-utilitarians are vulnerable to succumbing to “utility cascades”, that these cascades function to frustrate the ultimate goals of act-utilitarians, and that one apposite way (...) to avoid them is by “ostriching”: ignoring relevant evidence. If true, this conclusion would have remarkable consequences for act-utilitarianism and the effective altruism movement. However, Hayward is mistaken – albeit in an interesting way and with broader significance for moral philosophy. His argument trades on a subtle mischaracterization of act-utilitarianism. Act-utilitarians are not especially vulnerable to utility cascades, and they shouldn't ostrich. (shrink)