SUMMARY
Historically, the harmoniai, presenting the central concept of Plato’s discussion of music, should be interpreted as musical scales. Yet it is difficult to explain, in which way musical scales could assume ethical characters, as asserted by Plato. Socrates, while acknowledging his ignorance of the harmoniai, asserts that there is a need to retain two harmoniai representing two different ways of life. This wording suggests that rather than commenting on music of his time, Plato just by way of theoretical speculation envisaged a need to introduce a concept by which the differences in music could be explained. Thus, rather than the actual scales, the harmoniai appear to be a concept without a specific meaning; a concept that would be able to assume any technical characteristics of music, not yet explored in Plato’s time, however, that could explain the ethical characters of actual melodies.