A trade body argued: 'A law that is never enforced is no law at all. The rule requiring shops to display their prices is never enforced in this town. Therefore shopkeepers here break no law when they leave their prices undisplayed.' The argument is flawed because:

The opening claim is true only in the loose sense that an unenforced rule has no practical force. The conclusion uses 'law' in the strict sense of what is on the statute book, and in that sense the rule remains a law and is still being broken. The argument goes through only by letting the word change meaning midway. The other options raise side issues that leave this shift untouched.