The surface meaning is straightforward: responding to animosity with more animosity only perpetuates conflict. The quote asserts that the only effective antidote to hatred is its opposite, love. This is presented not as a mere suggestion, but as an 'eternal rule,' implying a fundamental law of existence.

Within the Buddhist framework, this principle is deeply rooted in the understanding of dependent origination (pratītyasamutpāda). Hatred arises from ignorance (avidyā) and attachment (upādāna), creating a cycle of suffering (dukkha). When you meet hatred with hatred, you are reinforcing the very conditions that give rise to it, strengthening the karmic chain. Conversely, cultivating love (mettā) and compassion (karuṇā) directly counteracts these root causes. Mettā, as taught by the Buddha, is a boundless, unconditional goodwill that aims to benefit all beings. By actively practicing mettā, you disrupt the arising of aversion, not just in yourself but potentially in others, thereby breaking the cycle of negative karma and moving towards liberation (nirvāṇa).

In your life: When faced with someone's anger or ill-will, consciously choose to respond with a calm, empathetic stance, even if it feels difficult. This practice weakens the impulse to retaliate and opens a path to de-escalation and inner peace.