In the year 380 BC, the philosopher Plato declared that changing the musical modes of a state would cause a wide-scale social revolution. This was not merely an aesthetic preference but a political imperative rooted in the belief that specific scales could harden the character of soldiers or soften them into submission. Plato argued that music in the Dorian or Phrygian harmoniai should be encouraged to build courage, while Lydian, Mixolydian, and Ionian harmoniai were to be banned for their perceived ability to induce weakness and moral decay. The ancient Greeks did not view these scales simply as collections of notes but as living entities that dictated the ethical state of the listener. A melody in the Dorian mode was thought to instill a sense of seriousness and stability, whereas the Phrygian mode was believed to incite anger and passion. This concept, known as ethos, linked the mathematical ratios of intervals directly to the moral fabric of society, creating a system where the choice of a scale was a choice of character.