 An action is what is produced by the operation of this desire, and so this desire amounts to the constitutive aim of action (in something like the way, Velleman thinks, that truth is the constitutive aim of belief [2015, ch. 10]). It will thus serve to determine what putative reasons for action are (good) practical reasons (in something like the way that truth determines what reasons for belief are good reasons). But then its content cannot quite be: to act for reasons. For that would amount to a viciously circular and vacuous specification of the constitutive aim of action.