The corruption of the best things gives rise to the worst.

The saying expresses a moral-psychological observation: when something intrinsically valuable—virtue, religion, reason, political power, love—is distorted or weaponized, its very excellence can amplify the harm it causes. A corrupted “best thing” often carries authority, trust, or emotional force, so its perversion can justify cruelty, intensify fanaticism, or enable systemic abuse more effectively than an openly “bad” thing could. The line also implies a caution about idealism: the higher the claim to goodness, the greater the vigilance required against self-deception and institutional decay. In Humean terms, it resonates with skepticism about human motives and the ease with which passions and interests can masquerade as moral principle.