PROP. VI. The force of any passion or emotion can overcome the rest of a man’s activities or power, so that the emotion becomes obstinately fixed to him.

Proof.—The force and increase of any passion and its persistence in existing are defined by the power of an external cause compared with our own (by the foregoing Prop.); therefore (IV. iii.) it can overcome a man’s power, &e. Q.E.D.