Marxist–Leninist atheism, also known as Marxist–Leninist scientific atheism, is the antireligious element of Marxism–Leninism.Institute of Scientific Atheism of the Academy of Social Sciences (1981). Questions of Scientific Atheism: “Marxist–Leninist atheism, with all its content is directed to the development of the abilities of the individual [person], religion deprives a person of his [and her] own “I”, doubles consciousness, creates conditions for him. . . . ” Based on a dialectical-materialist understanding of humanity's place in nature, Marxist–Leninist atheism proposes that religion is the opium of the people; thus, Marxism–Leninism advocates atheism, rather than religious belief.Kruglov, Anatoly Agapeevich. (Belarus, 1983). Fundamentals of Scientific Atheism: “The highest form is Marxist–Leninist atheism. * It relies on a materialistic understanding, not only of Nature (which was typical of pre–Marxist atheism) but also of society. . . .”In Novaya Zhizn No. 28, 3 December 1905, Marxists Internet Archive, Lenin said that: "Religion is one of the forms of spiritual oppression, which everywhere weighs down heavily upon the masses of the people, over-burdened by their perpetual work for others, by want and isolation . . . Those who toil and live in want all their lives are taught, by religion, to be submissive and patient while here on Earth, and to take comfort in the hope of a heavenly reward. . . . Religion is opium for the people. Religion is a sort of spiritual booze, in which the slaves of capital drown their human image, their demand for a life more or less worthy of Man." Marxists Internet Archive

To support those ideological premises, Marxist–Leninist atheism proposes an explanation for the origin of religion and explains methods for the scientific criticism of religion. The philosophic roots of Marxist–Leninist atheism appear in the works of Georg Wilhelm Friedrich Hegel (1770–1831), of Ludwig Feuerbach (1804–1872), of Karl Marx (1818–1883) and of Vladimir Lenin (1870–1924).Slovak Studies, Volume 21. The Slovak Institute in North America. p. 231. "The origin of Marxist–Leninist atheism, as understood in the USSR, is linked with the development of the German philosophy of Hegel and Feuerbach."

Marxist–Leninist atheism has informed public policy in various countries, such as the Soviet Union (1922-1991) and the People's Republic of China (1949- ), for example. Some non-Soviet Marxists have opposed this antireligious stance, and certain forms of Marxist thinking, such as the liberation theology movements in Latin America, have rejected Marxist–Leninist atheism entirely, and some Marxist-Leninist states, like Vietnam, Laos and post-Fidel Castro Cuba, abandoned anti-religious thinking and policies in favor of cooperation between religious bodies and the state for the promotion of socialism and anti-imperialism.

Philosophical bases Ludwig Feuerbach

In training as a philosopher in the early 19th century, Karl Marx participated in debates about the philosophy of religion, specifically about the interpretations presented in Hegelianism, i.e. "What is rational is real; and what is real is rational."Hegel, G.W.F., Elements of the Philosophy of Right (1821), Vorrede: Was vernünftig ist, das ist Wirklich; und was wirklich ist, das ist vernünftig. ["What is rational is real; and what is real is rational."] In those debates about reason and reality, the Hegelians considered philosophy an intellectual enterprise in service to the insights of Christian religious comprehension, which Georg Wilhelm Friedrich Hegel had elaborately rationalized in The Phenomenology of Spirit (1807). Although critical of contemporary religion, as a 19th-century intellectual, Hegel pursued the ontology and the epistemology of Christianity, as a personal interest compatible with Christian theological explanations of Dasein — explanations of the questions of existence and of being — which he clarified, systematized, and justified in his philosophy.Dimitry V. Pospielovsky. A History of Soviet Atheism in Theory, and Practice, and the Believer, pp. 9–10.

After his death in 1831, Hegel's philosophy about being and existence was debated by the Young Hegelians and the materialist atheists — such as Ludwig Feuerbach — who rejected all religious philosophy as a way of running the world; Karl Marx sided with the philosophy of the materialist atheists. Feuerbach separated philosophy from religion in order to grant intellectual autonomy to philosophers in their interpretations of material reality. He objected to the religious basis of Hegel's philosophy of spirit in order to critically analyse the basic concepts of theology, and he redirected philosophy from the heavens to the Earth, to the subjects of human dignity and the meaning of life, of what is morality and of what is the purpose of existence,Feuerbach, Ludwig. Essence of Christianity, New York: Harper Torch Books, 1957. pp. 13–14. concluding that humanity as a species (but just not as individuals) possessed within itself all the attributes that merited worship and that people had created God as a reflection of these attributes.Feuerbach, Ludwig. Essence of Christianity, New York: Harper Torch Books, 1957. p. 152. About the conceptual separateness of Man from God, in The Essence of Christianity (1841), Feuerbach said:

But the idea of deity coincides with the idea of humanity. All divine attributes, all the attributes which make God God, are attributes of the [human] species — attributes which in the individual [person] are limited, but the limits of which are abolished in the essence of the species, and even in its existence, in so far as it has its complete existence only in all men taken together.

Feuerbach thought that religion exercised power over the human mind through "the promotion of fear from the mystical forces of the Heaven",Pospielovsky, Dimitry V. A History of Soviet Atheism in Theory, and Practice, and the Believer, vol 1: A History of Marxist–Leninist Atheism and Soviet Anti–Religious Policies, St Martin's Press, New York (1987) p. 11. “. . . religious commitments should be intellectually and emotionally destroyed. . . . The catharsis of an intensive hatred towards the old God. . . . All previous religious institutions should be ruthlessly eradicated from the face of the Earth and from the memory of coming generations, so that they could never regain power over people's minds through deception and the promotion of fear from the mystical forces of the Heaven.” and with "an intensive hatred of the old God" said that houses of worship should be systematically destroyed and religious institutions eradicated. Experienced in that praxis of materialist philosophy, thought, and action, the apprentice Karl Marx became a radical philosopher.Pospielovsky, Dimitry V. A History of Soviet Atheism in Theory, and Practice, and the Believer, vol 1: A History of Marxist–Leninist Atheism and Soviet Anti–Religious Policies, St Martin's Press, New York (1987) p. 13. “It was obvious at this point that reading Feuerhach was not the only source of inspiration for [Karl] Marx’s atheism. The fascination with Feuerbach’s war against Christianity was, for young Marx, nothing more than an expression of his own readiness to pursue, in an anti-religious struggle, all the social and political extremes that materialistic determination required in principle. Yet, as David Aikman, in his most profound and erudite study of Marx and Marxism, notes, the clue to Marx’s passionate and violent atheism, or rather [his] anti-theism, cannot be found in an intellectual tradition, alone. He traces Marx’s anti-theism to the young Marx’s preoccupation with the Promethean cult of ‘Satan as a destroyer’.Pospielovsky, Dimitry V. A History of Soviet Atheism in Theory, and Practice, and the Believer, vol 1: A History of Marxist–Leninist Atheism and Soviet Anti–Religious Policies, St Martin's Press, New York (1987) p. 11. “At this point young Marx was completely fascinated by Feuerbach’s ‘humanistic zest’, and he adopted Feuerbach’s open rebellion against the powerful tradition of Christianity, unconditionally, as an intellectual revelation. Very early in his career, Marx bought the seductive idea that the higher goals of humanity would justify any radicalism, not only the intellectual kind but the social and political as well.”

Karl Marx

In his rejection of all religious thought, Marx considered the contributions of religion over the centuries to be unimportant and irrelevant to the future of humanity. The autonomy of humanity from the realm of supernatural forces was considered by Marx as an axiomatic ontological truth that had been developed since ancient times, and he considered it to have an even more respectable tradition than Christianity.Pospielovsky, Dimitry V. A History of Soviet Atheism in Theory, and Practice, and the Believer, vol. 1: A History of Marxist–Leninist Atheism and Soviet Anti–Religious Policies, St Martin's Press, New York (1987) p. 12. “Obviously Marx began his own theory of reality with an incomplete intellectual disdain for everything that religious thought, represented, theoretically, practically or emotionally. The cultural contributions of religion over the centuries were dismissed as unimportant and irrelevant to the well-being of the human mind." Marx held that the churches invented religion to justify the ruling classes' exploitation of labour of the working classes, by way of a socially stratified industrial society; as such, religion is a drug that gives an emotional escape from the real world.Pospielovsky, Dimitry V. A History of Soviet Atheism in Theory, and Practice, and the Believer, vol 1: A History of Marxist–Leninist Atheism and Soviet Anti–Religious Policies, St Martin's Press, New York (1987) pg 12. "The cultural contributions of religion over the centuries were dismissed as unimportant and irrelevant to the well-being of the human mind." In A Contribution to the Critique of Hegel’s Philosophy of Right, Marx described the contradictory nature of religious sentiment, that:

Religious suffering is, at one and the same time, the expression of real suffering, and a protest against real suffering. Religion is the sigh of the oppressed creature, the heart of a heart-less world, and the soul of soul-less conditions. It [religion] is the opium of the people.Marx, K.H. 1976. Introduction to A Contribution to the Critique of Hegel’s Philosophy of Right. Collected Works, vol. 3. New York.

Thus for Marx atheist philosophy liberated men and women from suppressing their innate potential as human beings, and allowed people to intellectually understand that they possess individual human agency, and thus are masters of their individual reality, because the earthly authority of supernatural deities is not real. Marx opposed the social-control function of religion, which the churches realised by way of societal atomization; the anomie and the social alienation that psychologically divide human beings from themselves (as individual men and women) and that alienate people from each other (as parts of a social community). Hence, the social authority of theology (religious ideology) must be removed from the law, the social norms, and the traditions with which men govern society. In that vein of political emancipation, represented in the culturally progressive concepts of citizen and citizenship as a social identity, in On the Jewish Question, Marx said that: