 Two final arguments against the possibility of obligatory grateful behavior concern the motivation and reasons on which the grateful beneficiary acts. The first begins with the premise that acts of gratitude must be done spontaneously, or from natural inclination, in order to count as acts of gratitude. Moral obligations, however, are supposed to be the sorts of things we can fulfill even if natural inclination is lacking, by exerting an effort of will. For example, I can fulfill an obligation of justice even if I do not act from natural inclination, when I grudgingly repay a steep loan, for instance; and so it seems I can have obligations of justice. By contrast, the possibility of a moral obligation to laugh at a joke seems absurd, in part, because laughter is something that can only be done spontaneously or from natural inclination (Card 1988). Insofar as acts of gratitude must be done from natural inclination, the argument goes, such acts cannot be done by exerting an effort of will, and thus cannot be morally obligatory (Card 1988; Wellman 1999b). This argument may be vulnerable to the objection that the initial premise (that acts of gratitude must be done from natural inclination to count as such) is false (see  section 3.4.2).