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.
Pope Pius XIWhat could ever be a sufficient reason for excusing in any way the direct murder of the innocent? This is precisely what we are dealing with here. Whether inflicted upon the mother or upon the child, it is against the precept of God and the law of nature: 'Thou shalt not kill.'
Pope Pius XIThe 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 XIMen will see in their king or in their rulers men like themselves perhaps unworthy or open to criticism, but they will not on that account refuse obedience if they see reflected in them the authority of Christ, God and Man. Peace and harmony, too, will result; for with the spread and the universal extension of the kingdom of Christ, men will become more and more conscious of the link that binds them together, and thus many conflicts will either be prevented entirely or at least their bitterness be diminished.
Pope Pius XIFor what will it profit men that a more prudent distribution and use of riches make it possible for them to gain even the whole world, if thereby they suffer the loss of their own souls? What will it profit to teach them sound principles in economics, if they permit themselves to be so swept away by selfishness, by unbridled and sordid greed, that hearing the commandments of the Lord, they do all things contrary.
Pope Pius XI