A target isn't set up so you can miss it. In the same way, evil doesn't exist in the world by nature.
As a mark[1] is not set up for the sake of missing the aim, so neither does the nature of evil exist in the world.
You can learn what's natural by looking at things everyone agrees on. When your neighbor's kid breaks a cup, you quickly say, "These things happen." So when your own cup breaks, you should react the same way you did when someone else's cup broke. Now apply this to bigger things. Is someone else's child or spouse dead? Everyone says, "That's just part of life." But when your own child dies, you immediately cry, "Oh, how miserable I am!" Always remember how you react when you hear the same news about other people.
The will of nature may be learned from things upon which we are all agreed. As when our neighbor’s boy has broken a cup, or the like, we are ready at once to say, “These are casualties that will happen”; be assured, then, that when your own cup is likewise broken, you ought to be affected just as when another’s cup was broken. Now apply this to greater things. Is the child or wife of another dead? There is no one who would not say, “This is an accident of mortality.” But if anyone’s own child happens to die, it is immediately, “Alas! how wretched am I!” It should be always remembered how we are affected on hearing the same thing concerning others.