But there is an important exception to the liberal “It’s OK to stigmatize an unhealthy lifestyle” rule: Unhealthy sexual behavior is still beyond reproach. Even grotesque levels of promiscuity require value-neutrality, though they can lead to crippling disease or death; they’re only objectionable if their participants fail to use the prescribed prophylactics, and only on that ground.

The government’s Plan B decision-making involved a fascinating caveat that undercuts the claim that it was an exclusively “scientific” judgment based on known health effects. The White House thinks young teens should have access to Plan B — but only the one-dose version. There wasn’t enough data that the generic two-dose version can be used responsibly by such juveniles without the intervention of a health provider, a Food and Drug Administration spokesman told the Times.

So a 15-year-old is mature enough to have sex and take one pill afterward to clean up any undesired results, but not mature enough to have sex and then take two pills.

The distinction is absurd and, frankly, terrifying. If a 15-year-old can’t be trusted to have the discipline to take a sequence of a mere two pills, it’s preposterous to think that she should be having sex, with all its life-changing consequences.