Letters 124.4

Reason, however, is surely the governing element in such a matter as this; as reason has made the decision concerning the happy life, and concerning virtue and honour also, so she has made the decision with regard to good and evil. For with them the vilest part is allowed to give sentence about the better, so that the senses—dense as they are, and dull, and even more sluggish in man than in the other animals,—pass judgment on the Good.

Seneca, Letters to Lucilius 124.4, translated by Richard Mott Gummere