The ultimate consequences of the individualist spirit in economic life are those which you yourselves, Venerable Brethren and Beloved Children, see and deplore: Free competition has destroyed itself; economic dictatorship has supplanted the free market; unbridled ambition for power has likewise succeeded greed for gain; all economic life has become tragically hard, inexorable, and cruel.
Pope Pius XICommunism teaches and seeks two objectives: unrelenting class warfare and the complete eradication of private ownership.
Pope Pius XIAlways moved by religious motives, the Church has condemned the various forms of Marxist Socialism; and she condemns them today, because it is her permanent right and duty to safeguard men from currents of thought and influence that jeopardize their eternal salvation.
Pope Pius XIThis organic conception of society, the only vital conception, combines a noble humanism with the genuine Christian spirit, and it bears the inscription from Holy Writ which St. Thomas has explained: "The work of justice shall be peace"; a text applicable to the life of a people whether it be considered in itself or in its relations with other nations.
Pope Pius XIThis [the opening of the Vatican City radio station built by Marconi earlier in 1931] was a new demonstration of the harmony between science and religion that each fresh conquest of science ever more luminously confirms, so that one may say that those who speak of the incompatibility of science and religion either make science say that which it never said or make religion say that which it never taught.
Pope Pius XIIf 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.
Pope Pius XI