Anger: an acid that can do more harm to the vessel in which it is stored than to anything on which it is poured.

The image treats anger as a corrosive substance: it damages the person who “stores” it more reliably than it harms the person at whom it is directed. The “vessel” is the self—mind, character, and even body—suggesting that resentment and rage eat away at judgment, health, and moral steadiness. The metaphor aligns with Stoic ethics in which passions are seen as destructive disturbances that enslave reason; the wise person aims to prevent anger from taking hold, not merely to vent it. The quote’s enduring appeal lies in its practical warning: indulging anger is self-injury disguised as retaliation.