We are inclined to look upon bad temper as a very harmless weakness; and yet here, right in the heart of this analysis of love, it finds a place; and the Bible again and again returns to condemn it as one of the most destructive elements in human nature. What is it made of? Jealousy, anger, pride, cruelty, self-righteousness, touchiness, stubbornness, sullenness. It is a test for love, a symptom, a revelation of an unloving nature at bottom. It is the intermittent fever which suggests a steadily growing disease within; the occasional bubble escaping to the surface which betrays some rottenness underneath; a sample of the hidden fruit of the soul dropped involuntarily when off one’s guard. In a word, it is the lightning form of a hundred un-Christian sins. For a lack of patience, a lack of kindness, a lack of generosity, and a lack of courtesy are all instantaneously symbolized in one flash of temper.
The Origin of the Organic World – Part One