Letters 88.9

Now I will transfer my attention to the musician. You, sir, are teaching me how the treble and the bass are in accord with one another, and how, though the strings produce different notes, the result is a harmony; rather bring my soul into harmony with itself, and let not my purposes be out of tune. You are showing me what the doleful keys are; show me rather how, in the midst of adversity, I may keep from uttering a doleful note.

Seneca, Letters to Lucilius 88.9, translated by Richard Mott Gummere