
— Immanuel Kant German philosopher 1724 - 1804
Metaphysical Elements of Ethics (1780). Translated by Thomas Kingsmill Abbott, translation available at Philosophy.eserver.org http://philosophy.eserver.org/kant/metaphys-elements-of-ethics.txt. From section "Preliminary Notions of the Susceptibility of the Mind for Notions of Duty Generally", Part C ("Of love to men")