“And they were both naked, the man and his wife, and were not ashamed.” So ends Chapter 2 of Genesis. Chapter 3 narrates the Fall and its aftermath: “The eyes of them both were opened, and they knew that they were naked; and they sewed fig leaves together, and made themselves aprons.” Presumably, they made themselves aprons to cover their nakedness, because they were now ashamed.

Why were Adam and Eve ashamed? And why hadn't they been ashamed before? The text of Genesis 3 suggests that they became ashamed because they realized that they were naked. But what realization was that? They were not created literally blind, and so they weren't seeing their own skin for the first time. The realization that they were naked must have been the realization that they were unclothed, which would have required them to envision the possibility of clothing. Yet the mere idea of clothing would have had no effect on Adam and Eve unless they also saw why clothing was necessary. And when they saw the necessity of clothing, they were seeing – what, exactly? There was no preexisting culture to disapprove of nakedness or to enforce norms of dress. What Genesis suggests is that the necessity of clothing was not a cultural invention but a natural fact, evident to the first people whose eyes were sufficiently open.

Or, rather, this fact was brought about by their eyes' being opened.