“Exploitation of the weaker living being by the stronger is the natural law of existence; there is always an attempt to devour the weak in different kingdoms of living beings. There is no possibility of checking this tendency by any artificial means under material conditions; it can be checked only by awakening the spiritual sense of the human being by practice of spiritual regulations.” (Shrila Prabhupada, Shrimad Bhagavatam, 1.13.47 Purport)