Anger is a killing thing: it kills the man who angers, for each rage leaves him less than he had been before — it takes something from him.

L’Amour frames anger not as a momentary emotion but as a corrosive force that diminishes the person who indulges it. The “killing” is primarily inward: each outburst erodes self-command, judgment, and moral stature, leaving the angry person “less” than before. The image suggests cumulative damage—rage becomes a habit that steadily consumes the self, narrowing one’s capacity for patience, empathy, and clear action. Implicitly, the quote advocates restraint and discipline: mastering anger is portrayed as self-preservation, while venting it is a kind of self-harm that also risks harming others.