Letters 106.9

Furthermore, any object that has power to move, force, restrain, or control, is corporeal. Come now! Does not fear hold us back? Does not boldness drive us ahead? Bravery spur us on, and give us momentum? Restraint rein us in and call us back? Joy raise our spirits? Sadness cast us down?

Seneca, Letters to Lucilius 106.9, translated by Richard Mott Gummere