Communism (and Socialism)

Communism is the most logical and extreme form of Socialism, outcome of the revolutionary theory of Karl Marx. The underlying philosophy is materialistic and determinist; the social order evolves through economic struggles between the classes in the direction of the violent revolution and a dictatorship of the proletariat, to be followed by a "withering away" of the state and the substitution of a society where ownership of all things is common, where all will work voluntarily, and all take freely of goods produced according to his needs.  As well as the abstract theory of Communism there must, since 1917, be considered the concrete attempt to apply its principals in the Union of Soviet Socialist Republics, where one aspect of it can be summed up in the words of Stalin: "Scientifically speaking, the dictatorship of the proletariat is a power which is restricted by no laws, hampered by no rules, and based directly on violence."
Whether in theory or in practice, the Church utterly rejects Communism on account of its errors, notably: its atheistic materialism, its doctrine and practice of class-war, its denial of the rights and liberties of the human person, including the natural right to possess some measure of private property, and its contempt for good morals under several heads.
Communism has been repeatedly condemned by the Holy See, notably by Pope Pius XI in the encyclical letter, Divini Redemptoris.

(Definition from A Catholic Dictionary, 1951)
 

Church Teaching on Communism:

• "This all too imminent danger, Venerable Brethren, as you have already surmised, is bolshevistic and atheistic Communism, which aims at upsetting the social order and at undermining the very foundations of Christian civilization" Encyclical On Atheistic Communism by Pope Pius XI, 1937
• "With reference to Communism, Our Venerable Predecessor, Pius IX, of holy memory, as early as 1846 pronounced a solemn condemnation, which he confirmed in the words of the Syllabus directed against "that infamous doctrine of so-called Communism which is absolutely contrary to the natural law itself, and if once adopted would utterly destroy the rights, property and possessions of all men, and even society itself."[1] Later on, another of Our predecessors, the immortal Leo XIII, in his Encyclical Quod Apostolici Muneris, defined Communism as "the fatal plague which insinuates itself into the very marrow of human society only to bring about its ruin."" Encyclical On Atheistic Communism by Pope Pius XI, 1937
• "In 1924 when Our relief-mission returned from the Soviet Union We condemned Communism in a special Allocution[3] which We addressed to the whole world. In our Encyclicals Miserentissimus Redemptor,[4] Quadragesimo Anno,[5] Caritate Christi,[6] Acerba Animi,[7] Dilectissima Nobis,[8] We raised a solemn protest against the persecutions unleashed in Russia, in Mexico and now in Spain." Encyclical On Atheistic Communism by Pope Pius XI, 1937
• "In fact, the most persistent enemies of the Church, who from Moscow are directing the struggle against Christian civilization, themselves bear witness, by their unceasing attacks in word and act, that even to this hour the Papacy has continued faithfully to protect the sanctuary of the Christian religion, and that it has called public attention to the perils of Communism more frequently and more effectively than any other public authority on earth." Encyclical On Atheistic Communism by Pope Pius XI, 1937
• "The doctrine of modern Communism, which is often concealed under the most seductive trappings, is in substance based on the principles of dialectical and historical materialism previously advocated by Marx, of which the theoricians of bolshevism claim to possess the only genuine interpretation. According to this doctrine there is in the world only one reality, matter, the blind forces of which evolve into plant, animal and man. Even human society is nothing but a phenomenon and form of matter, evolving in the same way. By a law of inexorable necessity and through a perpetual conflict of forces, matter moves towards the final synthesis of a classless society. In such a doctrine, as is evident, there is no room for the idea of God; there is no difference between matter and spirit, between soul and body; there is neither survival of the soul after death nor any hope in a future life. Insisting on the dialectical aspect of their materialism, the Communists claim that the conflict which carries the world towards its final synthesis can be accelerated by man. Hence they endeavor to sharpen the antagonisms which arise between the various classes of society. Thus the class struggle with its consequent violent hate and destruction takes on the aspects of a crusade for the progress of humanity. On the other hand, all other forces whatever, as long as they resist such systematic violence, must be annihilated as hostile to the human race.
  Communism, moreover, strips man of his liberty, robs human personality of all its dignity, and removes all the moral restraints that check the eruptions of blind impulse. There is no recognition of any right of the individual in his relations to the collectivity; no natural right is accorded to human personality, which is a mere cog-wheel in the Communist system. In man's relations with other individuals, besides, Communists hold the principle of absolute equality, rejecting all hierarchy and divinely-constituted authority, including the authority of parents. What men call authority and subordination is derived from the community as its first and only font. Nor is the individual granted any property rights over material goods or the means of production, for inasmuch as these are the source of further wealth, their possession would give one man power over another. Precisely on this score, all forms of private property must be eradicated, for they are at the origin of all economic enslavement." Encyclical On Atheistic Communism by Pope Pius XI, 1937
• "Such, Venerable Brethren, is the new gospel which bolshevistic and atheistic Communism offers the world as the glad tidings of deliverance and salvation! It is a system full of errors and sophisms. It is in opposition both to reason and to Divine Revelation. It subverts the social order, because it means the destruction of its foundations; because it ignores the true origin and purpose of the State; because it denies the rights, dignity and liberty of human personality." Encyclical On Atheistic Communism by Pope Pius XI, 1937
• "See to it, Venerable Brethren, that the Faithful do not allow themselves to be deceived! Communism is intrinsically wrong, and no one who would save Christian civilization may collaborate with it in any undertaking whatsoever. Those who permit themselves to be deceived into lending their aid towards the triumph of Communism in their own country, will be the first to fall victims of their error. And the greater the antiquity and grandeur of the Christian civilization in the regions where Communism successfully penetrates, so much more devastating will be the hatred displayed by the godless" Encyclical On Atheistic Communism by Pope Pius XI, 1937
• "You are aware indeed, that the goal of this most iniquitous plot is to drive people to overthrow the entire order of human affairs and to draw them over to the wicked theories of this Socialism and Communism, by confusing them with perverted teachings. But these enemies realize that they cannot hope for any agreement with the Catholic Church, which allows neither tampering with truths proposed by faith, nor adding any new human fictions to them. This is why they try to draw the Italian people over to Protestantism, which in their deceit they repeatedly declare to be only another form of the same true religion of Christ, thereby just as pleasing to God. Meanwhile they know full well that the chief principle of the Protestant tenets, i.e., that the holy scriptures are to be understood by the personal judgment of the individual, will greatly assist their impious cause. They are confident that they can first misuse the holy scriptures by wrong interpretation to spread their errors and claim God's authority while doing it. Then they can cause men to call into doubt the common principles of justice and honor" Encyclical On the Church in the Pontifical States by Pope Pius IX, 1849
• Like every other apostolate, the lay apostolate has two objectives: to preserve and to win over. The present-day Church must give the closest attention to both of these. Putting it succinctly, Christ's Church has no intention of yielding ground to her avowed enemy, atheistic communism, without a struggle. This battle will be fought to the end, but with the weapons of Christ!" Encyclical On Guiding Principles of the Lay Apostolate by Pope Pius XII to the Second World Congress of the Lay Apostolate, 1957
• "There are some who show themselves fearful and uncertain when faced with the wickedness of communism which aims to rob of their faith the very ones to whom it promises material prosperity. But documents recently issued by this Holy See have shown clearly the way to be followed, the path from which no one must stray unless he wishes to fail in his duty" Apostolic Exhortation of Pope Pius XII To the Clergy of the Entire World
• "Moreover, not content with removing religion from public society, they wish to banish it also from private families. For, teaching and professing the most fatal error of "Communism and Socialism," they assert that "domestic society or the family derives the whole principle of its existence from the civil law alone; and, consequently, that on civil law alone depend all rights of parents over their children, and especially that of providing for education." Encyclical On Condemning Current Errors by Pope Pius IX, 1864
• "To this goal also tends the unspeakable doctrine of Communism, as it is called, a doctrine most opposed to the very natural law. For if this doctrine were accepted, the complete destruction of everyone's laws, government, property, and even of human society itself would follow." Encyclical On Faith and Religion by Pope Pius IX, 1846
• "IV. SOCIALISM, COMMUNISM, SECRET SOCIETIES, BIBLICAL SOCIETIES, CLERICO-LIBERAL SOCIETIES
  Pests of this kind are frequently reprobated in the severest terms in the Encyclical "Qui pluribus," Nov. 9, 1846, Allocution "Quibus quantisque," April 20, 1849, Encyclical "Noscitis et nobiscum," Dec. 8, 1849, Allocution "Singulari quadam," Dec. 9, 1854, Encyclical "Quanto conficiamur," Aug. 10, 1863" THE SYLLABUS OF ERRORS CONDEMNED BY PIUS IX, 1864
• "Hence we have reached the limit of horrors, to wit, communism, socialism, nihilism, hideous deformities of the civil society of men and almost its ruin. And yet too many attempt to enlarge the scope of these evils, and under the pretext of helping the multitude, already have fanned no small flames of misery. The things we thus mention are neither unknown nor very remote from us" Encyclical On the Origin of Civil Power by Pope Leo XIII, 1881
• "In this way We daily see the numerous ills which afflict all classes of men. These poisonous doctrines have utterly corrupted both public and private life; rationalism, materialism, atheism, have begotten socialism, communism, nihilism-evil principles which it was not only fitting should have sprung from such parentage but were its necessary offspring" Encyclical On The Right Ordering of Christian Life by Pope Leo XIII, 1888
• "The Holy Virgin who once victoriously drove the terrible sect of the Albigenses from Christian countries, now suppliantly invoked by us, will turn aside the new errors, especially those of Communism, which reminds us in many ways, in its motives and misdeeds, of the ancient ones" Encyclical On the Rosary by Pope Pius XI, 1937
• If Socialism, like all errors, contains some truth (which, moreover, the Supreme Pontiffs have never denied), it is based nevertheless on a theory of human society peculiar to itself and irreconcilable with true Christianity. Religious socialism, Christian socialism, are contradictory terms; no one can be at the same time a good Catholic and a true socialist." Encyclical On the Reconstruction of the Social Order by Pope Pius XI, 1931
   

Summary

It is clear from past Church teaching that no true Catholic can ever be a Communist, or condone Communism.