We must learn to endure what we cannot avoid. Our life is composed, like the harmony of the world, of contrary things, also of different ones, sweet and harsh, sharp and flat, soft and loud. If a musician liked only one kind, what would he have to say? He must know how to use them together and blend them.. And so must we do with good and evil, which are con substantial with our life. Our existence is impossible without this mixture, and one element is no less necessary for it than the other.