"Ordinary human thinking is full of greed, jealousy, and pride. A man seeing another man on the street may immediately think, "He is better looking than I am." The instant result is envy or shame. A girl seeing another girl may think, "I am prettier than she is." The instant result is pride. This sort of comparison is a mental habit, and it leads directly to ill feeling of one sort or another: greed, envy, pride, jealousy, or hatred. It is an unskillful mental state, but we do it all the time."