Roman Catechism 28.32

Chapter 28 — Part III: The Decalogue — The Fifth Commandment

Section 32. Here also applies an argument which St. Chrysostom has ably and learnedly handled. It is that no man is injured but by himself. Let the man, who considers himself injured by another, consider the matter in the right way and he will certainly find that he has received no injury or loss from others. For although he may have experienced injury from external causes, he is himself his greatest enemy by wickedly staining his soul with hatred, malevolence and envy.