Common Sense Theory of the Origin of Evil.
Reading edition
What then is the cause or origin of evil as taught by reason and experience?
It is the eternal nature of things existing independently of the will of the Creator or of any other being.
What is the cause of the existence of this created system? It is the will of the Creator.
What is the cause or reason why God willed that this system should be as it is, with all the evil that exists? It is because it is the best system possible in the nature of things.
What is the cause or reason that any given event, however evil, is not prevented by God? It is because any change that would prevent it, would alter the best possible system, and thus make more evil than the one thus prevented.
[pg 145]