On May 15, we celebrate the anniversary of what can be called the most influential encyclical ever written, Rerum Novarum, and several of the relevant commemorative encyclicals of subsequent Popes.
We approach the subject with confidence, and in the exercise of the rights which manifestly appertain to Us, for no practical solution of this question will be found apart from the intervention of religion and of the Church. It is We who are the chief guardian of religion and the chief dispenser of what pertains to the Church; and by keeping silence we would seem to neglect the duty incumbent on us. Doubtless, this most serious question demands the attention and the efforts of others besides ourselves - to wit, of the rulers of States, of employers of labor, of the wealthy, aye, of the working classes themselves, for whom We are pleading. But We affirm without hesitation that all the striving of men will be vain if they leave out the Church.
It is the Church that insists, on the authority of the Gospel, upon those teachings whereby the conflict can be brought to an end, or rendered, at least, far less bitter; the Church uses her efforts not only to enlighten the mind, but to direct by her precepts the life and conduct of each and all; the Church improves and betters the condition of the working man by means of numerous organizations; does her best to enlist the services of all classes in discussing and endeavoring to further in the most practical way, the interests of the working classes; and considers that for this purpose recourse should be had, in due measure and degree, to the intervention of the law and of State authority.
It must be first of all recognized that the condition of things inherent in human affairs must be borne with, for it is impossible to reduce civil society to one dead level. Socialists may in that intent do their utmost, but all striving against nature is in vain.
Quadragesimmo Anno, 80 years:
[L]et no one think that all the socialist groups or factions that are not communist have, without exception, recovered their senses to this extent either in fact or in name. For the most part they do not reject the class struggle or the abolition of ownership, but only in some degree modify them. Now if these false principles are modified and to some extent erased from the program, the question arises, or rather is raised without warrant by some, whether the principles of Christian truth cannot perhaps be also modified to some degree and be tempered so as to meet Socialism half-way and, as it were, by a middle course, come to agreement with it. There are some allured by the foolish hope that socialists in this way will be drawn to us. A vain hope! Those who want to be apostles among socialists ought to profess Christian truth whole and entire, openly and sincerely, and not connive at error in any way. If they truly wish to be heralds of the Gospel, let them above all strive to show to socialists that socialist claims, so far as they are just, are far more strongly supported by the principles of Christian faith and much more effectively promoted through the power of Christian charity.
Mater et Magistra, 50 years:
We must solemnly proclaim that human life is transmitted by means of the family, and the family is based upon a marriage which is one and indissoluble and, with respect to Christians, raised to the dignity of a sacrament. The transmission of human life is the result of a personal and conscious act, and, as such, is subject to the all-holy, inviolable and immutable laws of God, which no man may ignore or disobey. He is not therefore permitted to use certain ways and means which are allowable in the propagation of plant and animal life.
Human life is sacred—all men must recognize that fact. From its very inception it reveals the creating hand of God. Those who violate His laws not only offend the divine majesty and degrade themselves and humanity, they also sap the vitality of the political community of which they are members.
Centesimus Annus, 20 years:
In every age the true and perennial "newness of things" comes from the infinite power of God, who says: "Behold, I make all things new" (Rev 21:5). These words refer to the fulfilment of history, when Christ "delivers the Kingdom to God the Father ... that God may be everything to everyone" (1 Cor 15:24,28). But the Christian well knows that the newness which we await in its fulness at the Lord's second coming has been present since the creation of the world, and in a special way since the time when God became man in Jesus Christ and brought about a "new creation" with him and through him (2 Cor 5:17; Gal 6:15).
John Paul II