Ad impossibilia nemo tenetur (À l'impossible nul n'est tenu) - on ne peut exiger de quiconque ce qu’il lui est impossible de faire.
Image par Renjith Krishnan
Boy do I love Texas!:
"It is illegal to drive without windshield wipers. You don't need a windshield, but you must have the wipers."
It's all in the details.