The Shoshone, as well as those peoples around the world who still survive at the least complex levels of social organization, know that romantic love exists. But they also recognize it for what it is—in their case, a form of madness.... they regard the participants with tolerance and patience, for they know that the illness will soon go away.... To them, only someone mentally backward would base an institution so important to survival as marriage on romantic love.... it is a life and death business.

Man's Rise to Civilization (1968)