Augustine of Hippo

Every rational soul is made unhappy by its sins or happy by its well doing. Every irrational soul yields to one that is more powerful, or obeys one that is better, or is on terms of equality with its equals, exercising rivals or harming any it has overcome. Every body is obedient to its soul so far as permitted by the merits of the latter or the orderly arrangement of things. There is no evil in the universe, but in individuals there is evil due to their own fault. When the soul has been regenerated by the grace of God and restored to its integrity and made subject to him alone by whom it was created, its body too will be restored to its original strength, and it will receive power to possess the world, not to be possessed by the world. Then it will have no evil. For the lowly beauty of temporal changes will not involve it, for it will have been raised above change. There will be, as it is written, a new heaven and a new earth, and there souls will not have to do their part in toiling but will reign over the universe. "All things are yours," says the apostle, "and you are Christ's and Christ is God's." And again: "The head of the woman is the man, the head of the man is Christ, and the head of Christ is God." Accordingly, since the vice of the soul is not its nature but contrary to its nature and is nothing else than sin and sin's penalty, we understand that no nature, or, if you prefer it, no substance or essence, is evil.