The American Pediatric Association is clear that spanking harms children. In light of this information, it’s fair to say spanking children is immoral and those who spank in this day and age are doing wrong. But here’s a tricky question. How should our moral judgments of the present impact our judgments of what people did in the past?

Is abortion the murder of an innocent child? Or the exercise of a woman’s right to control her own body? Or maybe we’re focusing on the wrong question.

Is it ever morally okay to punish people? To punish someone is to hurt them because of a wrong they’ve already committed—whether or not any future benefit will come of that hurt. How could it be okay to deliberately hurt someone?

The belief that some things are natural while others are unnatural is part of the common currency of human thought, but we rarely pause to consider exactly what it means to say that something is unnatural. It’s important to do so because this concept is politically very potent.