298 M. Hoffman et al. why we judge torture as worse than imprisonment or punishment (torture is harming someone as a means to obtaining information) and perhaps one of the (many) rea- sons we oppose prostitution (prostitution is having sex with someone as a means to obtaining money). The Envelope Game clarifies the function of adhering to this maxim. Whereas those who treat someone well as means to an end would also mistreat them if expedient, those who treat someone well as an end can be trusted not to mistreat them when expedient. Attention to Motives. The previous two applications are examples of a more gen- eral phenomenon: that we judge the moral worth of an action based on the motiva- tion of the actor, as argued by deontological ethicists, but contested by consequentialists. The deontological argument is famously invoked by Kant: “Action from duty has its moral worth not in the purpose to be attained by it but in the maxim in accordance with which it is decided upon, and therefore does not depend upon the realization of the object of the action but merely upon the principle of volition in accordance with which the action is done without regard for any object of the faculty of desire” (Kant, 1997). These applications illustrate that we attend to motives because they provide valuable information on whether the actor can be trusted to treat others well even when it is not in her interest. Altruism Without Prospect of Reciprocation. CWOL also helps explain why peo- ple cooperate in contexts where there is no possibility of reciprocation, such as in one-shot anonymous laboratory experiments like the dictator game (Fehr & Fischbacher, 2003), as well as when performing heroic and dangerous acts. Consider soldiers who throw themselves on a grenade to save their compatriots or stories like that of Liviu Librescu, a professor at the University of Virginia and a Holocaust sur- vivor, who saved his students during a school shooting. When he heard the shooter coming towar