That the word lunatic comes from the goddess of the moon, Luna is probably no surprise to most of you since the full moon has for years been blamed for increased crime and general mayhem. But have you ever stopped to wonder why that happened? Luna was, after all, a rather calm and cool goddess, so how did her name become associated with madness?
Before the birth of modern medicine, there was no good way to explain mental illness. Ancient Greek and Roman physicians believed that too much water in the brain was the cause. As the famous Greek physician Hippocrates stated, “Madness comes from the brain’s moisture.” Since the moon has a powerful effect on water, making tides rise and fall, physicians thought that the moon might also have an effect on the water in the brain and thus contribute to madness. They certainly did not see the moon as the main cause. But over time this changed. The moon and her waxing and waning ways gradually got the entire blame, so that in the 1200’s Thomas Aquinas wrote, “Demons harass men according to the phases of the moon.” Soon people who struggled with mental health were called lunatics and the disease lunacy. Fortunately Luna’s name survives in other, more positive, ways also such as lunar space missions and lunar calendars and other things that have to do with the moon.