On Anger, Book 1, Section 17 — In Plain English

Seneca — The Senator

Aristotle says that "certain emotions, if you use them properly, work like weapons." This would be true if emotions were like swords — if you could pick them up or put them down whenever you wanted. But these "weapons" that Aristotle calls virtuous don't work that way. They fight on their own. They don't wait for you to grab them. They possess you instead of you possessing them. We don't need external weapons anyway. Nature gave us everything we need when she gave us reason. She gave us this weapon that is strong, unbreakable, and obedient to our will. Unlike emotions, reason won't betray us or turn against us.

Seneca — The Senator Original

Aristotle says that “certain passions, if one makes a proper use of them, act as arms”: which would be true if, like weapons of war, they could be taken up or laid aside at the pleasure of their wielder. These arms, which Aristotle assigns to virtue, fight of their own accord, do not wait to be seized by the hand, and possess a man instead of being possessed by him. We have no need of external weapons, nature has equipped us sufficiently by giving us reason. She has bestowed this weapon upon us, which is strong, imperishable, and obedient to our will, not uncertain or capable of being turned against its master.