The excess of virtue is a vice.

This saying is commonly labeled a “Greek proverb” in modern quotation collections and reflects a broadly Greek ethical outlook associated with moderation (the ideal of avoiding extremes). In classical Greek moral thought—especially in traditions influenced by the “golden mean”—virtue is often understood as a balanced disposition between opposing excesses and deficiencies. The proverb’s sentiment aligns with the cultural suspicion of extremes (in behavior, emotion, or self-presentation) and the idea that even admirable qualities can become harmful when pushed beyond measure. However, it is typically transmitted as a general maxim rather than tied to a single identifiable ancient author or occasion.

The line warns that moral qualities are not automatically good in unlimited quantity: when a virtue is pursued without proportion, it can flip into a fault. Courage can become recklessness, frugality can become stinginess, honesty can become cruelty, and piety can become fanaticism. The proverb thus argues for practical wisdom—judgment about when, how, and to what degree a virtue should be exercised. Its significance lies in challenging simplistic moral arithmetic (“more virtue is always better”) and emphasizing balance, context, and restraint as essential to ethical life.