Plato believed that the soul is composed of three parts: reason, spirit, and desire. Each part has its own virtue, and in the case of spirit, its virtue is courage. Courage is the quality of facing difficulties, danger, or fear without being overcome by them. It is the ability to act bravely and confidently in challenging situations. According to Plato, having a well-balanced soul means that each part, including the spirited part, is virtuous, and in the case of spirit, this virtue is courage.