“Gratitude, as it were, is the moral memory of mankind. . . . All external and internal motives that bind individuals together may be examined with respect to their implementation of the exchange which not only holds society together once it is formed but, in large measure, forms it. From such an examination, gratitude emerges as the motive which, for inner reasons, effects the return of a benefit where there is not external necessity for it. But ‘benefit’ is not limited to a person’s giving things to another: we also thank the artist or poet who does not even know us. This fact creates innumerable connections, ideal and concrete, loose and firm, among those who are filled with gratitude toward the same giver. In fact, we do not thank somebody only for what he does: the feeling with which we often react to the mere existence of a person, must itself be designated as gratitude. We are grateful to him only because he exists, because we experience him. Often the subtlest as well as firmest bonds among men develop from this feeling.”