The separation of play from work is a problem only in the human world.  So is the difference between art and nature, or an intellectual accomplishment and a physical one.  As a result, we celebrate play, art, and invention as leaps into the unknown; however, any imbalance can send us back to nostalgia for our primate past and the conviction that the basics of work, nature, and physical labour are somehow more worthwhile or even moral. In the same way, we have explored our sexuality as separable from conception: a pleasurable, empathetic bridge to strangers of the same species.  We have even invented contraception—a skill that has probably existed in some form since our ancestors figured out the process of birth—in order to extend this uniquely human difference.  Yet we also have times of atavistic suspicion that sex is not complete—or even legal or intended by God—if it cannot end in conception. (from Gloria Steinem, "Erotica vs. Pornography: A Clear and Present Difference" [edited])
The break should occur where Steinem changes from writing about different artificial separations in society to writing specifically about the separation of sex and procreation.