Wrath was sinful because of the social problems it caused, sometimes even homicide. It served to ignore those who are present, contradicts those who are absent, produces insults, and responds harshly to insults that are received. Aristotle felt that anger or wrath was a natural outburst of self-defense in situations where people felt they had been wronged. Aquinas felt that if anger was justified, it was not a sin. For example, "He that is angry without cause, shall be in danger; but he that is angry with cause, shall not be in danger: for without anger, teaching will be useless, judgments unstable, crimes unchecked. Therefore to be angry is not always an evil."