Sigmund Freud, in his 1930 essay Civilization and Its Discontents, argues that thesublimation of sexual desire leads to the mental energy required for advances in civiliza-tion: science, art, politics, etc.

In particular, he writes, "Sublimation of instinct [such as sexual instinct] is an especially conspicu-ous feature of cultural development; it is what makes it possible for higherpsychical activities, scientific, artistic, or ideological, to play such an impor-tant part in civilized life... it is impossible to overlook the extent to which civilization is built up upon a renunciation of instinct..."

How would an economist phrase Freud's argument, in terms of opportunity costs? Might this explain the development of monogamous marriage as an institution?