“Insane’ probably means to have an innate mental problem, something that calls for professional treatment, while ‘lunatic’ means to have your sanity temporarily seized by the luna, which is ‘moon’ in Latin. In nineteenth-century England, if you were a certified lunatic and you committed a crime, the severity of the crime would be reduced a notch. The idea was that the crime was not so much the responsibility of the person himself as that he was led astray by the moonlight. Believe it or not, laws like that actually existed. In other words, the fact that the moon can drive people crazy was actually recognized in law.”