 Marx’s ideas concerning alienation were greatly influenced by the critical writings on religion of Ludwig Feuerbach (1804–1872), and especially his The Essence of Christianity (1841). One key text in this respect is Marx’s “Contribution of Hegel’s Critique of Right: Introduction” (1843). This work is home to Marx’s notorious remark that religion is the “opium of the people,” a harmful, illusion-generating painkiller (MECW 3: 175). It is here that Marx sets out his account of religion in most detail.