Diet Coke, Contraception, and Natural Law Theory

a glitch in the perverted faculty argument

literally me

“There are philosophers who have written pages trying to figure out whether it is morally permissible to chew gum just for the pleasant taste of it. Relax, dude. Have a cookie.” — John Corvino, What’s Wrong With Homosexuality?, p. 18.

As I write to you, dear reader, I am drinking diet coke through a straw.

I don’t take many things to be utterly obvious in this life: it’s not obvious whether God exists, whether my Substack is 1000x better than

Bentham's Bulldog

’s, or whether it’s simply 100x better plus interest. But here is one truth I hold to be self-evident: if I could avert the apocalypse by sipping diet coke, it would not be wrong for me to do so. (I also take it to be obvious that sipping diet coke is fine when nothing whatsoever is at stake — assuming there’s not something about my diet coke I don’t know, like that it was stolen, or squeezed from suffering shrimps.)

According to some critics of classical natural law theory, the view implies that seemingly benign actions like sipping diet coke and chewing sugarless gum are categorically wrong: wrong even if those actions would avert the apocalypse. According to defenders of classical natural law theory, the view implies no such thing, and these purported counterexamples can be undone in a couple of sentences.

It’s not obvious to me whether classical natural law theory — interpreted aright — implies the categorical wrongness of sipping Diet Coke or chewing on sugarless gum. But classical natural law theory wobbles on a delicate dialectical tightrope: on the one hand, natural lawyers want to derive the interesting sexual prohibitions of classical natural law theory (against homosexuality, masturbation, condom use, and the like); on the other, they obviously want to block wacky implications like that it’s wrong to drink Diet Coke.

In what follows, I want to shake this tightrope from both ends. It’s not clear to me, still, how natural lawyers can have their interesting sexual prohibitions and chew their chewing gum too. In what follows, I’ll lay out the case for why (the core insight of which, I think, is original to the present author).

The Perverted Faculty Argument

Classical natural lawyers defend something called the Perverted Faculty Argument (PFA) — this argument, if successful, shows that masturbation, gay sex, and artificial contraception are intrinsically evil.