<P> Gratitude, in its ordinary sense, is as much about having warm and benevolent feelings toward one's benefactors as it is about having obligations to them . Reciprocity, in its ordinary dictionary sense, is broader than that, and broader than all discussions that begin with a sense of mutuality and mutual benevolence . (See the reference below to Becker, Reciprocity, and the bibliographic essays therein .) Reciprocity pointedly covers arm's - length dealings between egoistic or mutually disinterested people . </P> <P> Moreover, norms of gratitude do not speak very directly about what feelings and obligations are appropriate toward wrongdoers, or the malicious . Reciprocity, by contrast, speaks directly to both sides of the equation--requiring responses in kind: positive for positive, negative for negative . In this, it also differs from the golden rule, which is compatible with forgiveness and "turning the other cheek" but has notorious difficulties as a basis for corrective justice, punishment, and dealing with people (e.g., masochists) who have unusual motivational structures . </P> <P> Finally, the idea of enforcing, or carrying out a duty of gratitude, as well as calibrating the extent one's gratitude, seems inconsistent with the warm and benevolent feelings of "being grateful ." There is a similar inconsistency in the idea of enforcing a duty to love . Reciprocity, by contrast, because it does not necessarily involve having special feelings of love or benevolence, fits more comfortably into discussions of duties and obligations . Further, its requirement of an in - kind response invites us to calibrate both the quality and the quantity of the response . </P> <P> The norm of reciprocity thus requires that we make fitting and proportional responses to both the benefits and harms we receive--whether they come from people who have been benevolent or malicious . Working out the conceptual details of this idea presents interesting questions of its own . The following matters are all considered at length in many of the sources listed below under References, and those authors typically defend particular proposals about how best to define the conceptual details of reciprocity . What follows here is simply an outline of the topics that are under philosophical scrutiny . </P>

When does a particular form of social interaction become political