Anger is a transient hatred or at least very like it.

South’s aphorism treats anger not as a momentary “heat” that can be morally excused, but as hatred in miniature—hatred compressed into a short duration. The point is ethical and psychological: even when anger passes quickly, it shares hatred’s structure (a hostile will toward another) and therefore carries similar dangers—distorted judgment, cruelty, and a readiness to harm. By calling it “transient,” South also implies that anger can be checked before it hardens into settled malice; the moral task is to interrupt the slide from sudden passion into enduring enmity. The line reflects a Christian moralist’s suspicion of passions that masquerade as righteous while corroding charity.