Ancient Greek physicians and philosophers historically connected the full moon to episodes of mental disturbance, particularly in individuals predisposed to instability. This wasn’t simply folklore; the belief was integrated into early medical understandings of the human mind. The full moon itself was viewed with a mixture of awe and apprehension in ancient Greece. While the exact reasoning remains debated, the connection suggests early attempts to identify external factors influencing mental health. Modern science has largely debunked a direct causal link, but the historical perception reveals insights into ancient Greek medical thought and cultural anxieties. The enduring association of the moon with madness continues to resonate in language and popular culture today.