Date: 380-360 B.C.

"The body is held together at a certain tension between the extremes of hot and cold, and dry and wet, and so on, and our soul is a temperament or adjustment of these same extremes, when they are combined in just the right proportion."

— Plato (427 BC - 347 BC)

Date: w. 350 B.C.

"Voice is a kind of sound characteristic of what has soul in it; nothing that is without soul utters voice, it being only by a metaphor that we speak of the voice of a flute or the lyre or generally of what (being without soul) possesses the power of producing a succession of notes which differ i...

— Aristotle (384-322 B.C.)