The encyclical Humani Generis of Pius XII gave a clear condemnation of neo-Modernism in the same way that Lamentabili of Pius X had condemned modernism 40 years earlier. The basic message is simple: the magisterium is the guardian and the interpreter of Divine Revelation. Any attempt to separate oneself from this magisterium would be to follow in the footsteps of Luther. But Lutheranism has humanized and fragmented Christianity, reducing it to a personal experience. It took only 15 years for the conciliar Church to undo what defenses Humani Generis had raised. Never before in the history of the Church had a dogmatic encyclical been so quickly and so completely disavowed by the very men who had fallen under its condemnation! Here we offer a few excerpts from this pivotal encyclical touching on faith: the undermining reefs of modern evolutionism and irenism, the limits of theology, the sure foundation of perennial philosophy.
1. Disagreement and error among men on moral and religious matters have always been a cause of profound sorrow to all good men, but above all to the true and loyal sons of the Church, especially today, when we see the principles of Christian culture being attacked on all sides.
2. It is not surprising that such discord and error should always have existed outside the fold of Christ. For though, absolutely speaking, human reason by its own natural force and light can arrive at a true and certain knowledge of the one personal God, Who by His providence watches over and governs the world, and also the natural law, which the Creator has written in our hearts, still there are not a few obstacles to prevent reason from making efficient and fruitful use of its natural ability. The truths that have to do with God and the relations between God and men, completely surpass the sensible order and demand self-surrender and self-abnegation in order to be put into practice and to influence practical life. Now the human intellect, in gaining the knowledge of such truths, is hampered both by the activity of the senses and the imagination, and by evil passions arising from original sin. Hence men easily persuade themselves in such matters that what they do not wish to believe is false or at least doubtful.
3. It is for this reason that divine revelation must be considered morally necessary so that those religious and moral truths which are not of their nature beyond the reach of reason in the present condition of the human race, may be known by all men readily with a firm certainty and with freedom from all error.
4. Furthermore the human intelligence sometimes experiences difficulties in forming a judgment about the credibility of the Catholic faith, notwithstanding the many wonderful external signs God has given, which are sufficient to prove with certitude by the natural light of reason alone the divine origin of the Christian religion. For man can, whether from prejudice or passion or bad faith, refuse and resist not only the evidence of the external proofs that are available, but also the impulses of actual grace.
5. If anyone examines the state of affairs outside the Christian fold, he will easily discover the principal trends that not a few learned men are following. Some imprudently and indiscreetly hold that evolution, which has not been fully proved even in the domain of natural sciences, explains the origin of all this, and audaciously support the monistic and pantheistic opinion that the world is in continual evolution. Communists gladly subscribed to this opinion so that, when the souls of men have been deprived of every idea of a personal God, they may the more efficaciously defend and propagate their dialectical materialism.
11. Another danger is perceived which is all the more serious because it is more concealed beneath the mask of virtue. There are many who, deploring disagreement among men and intellectual confusion, through an imprudent zeal for souls, are urged by a great and ardent desire to do away with the barrier that divides good and honest men; these advocate an “eirenism” according to which, by setting aside the questions which divide men, they aim not only at joining forces to repel the attacks of atheism, but also at reconciling things opposed to one another in the field of dogma. And as in former times some questioned whether the traditional apologetics of the Church did not constitute an obstacle rather than a help to the winning of souls for Christ, so today some are presumptive enough to question seriously whether theology and theological methods, such as with the approval of ecclesiastical authority are found in our schools, should not only be perfected, but also completely reformed, in order to promote the more efficacious propagation of the kingdom of Christ everywhere throughout the world among men of every culture and religious opinion.
12. Now if these only aimed at adapting ecclesiastical teaching and methods to modern conditions and requirements, through the introduction of some new explanations, there would be scarcely any reason for alarm. But some through enthusiasm for an imprudent “eirenism” seem to consider as an obstacle to the restoration of fraternal union, things founded on the laws and principles given by Christ and likewise on institutions founded by Him, or which are the defense and support of the integrity of the faith, and the removal of which would bring about the union of all, but only to their destruction.
21. It is also true that theologians must always return to the sources of divine revelation: for it belongs to them to point out how the doctrine of the living Teaching Authority is to be found either explicitly or implicitly in the Scriptures and in Tradition. Besides, each source of divinely revealed doctrine contains so many rich treasures of truth, that they can really never be exhausted. Hence it is that theology through the study of its sacred sources remains ever fresh; on the other hand, speculation which neglects a deeper search into the deposit of faith, proves sterile, as we know from experience. But for this reason even positive theology cannot be on a par with merely historical science. For, together with the sources of positive theology God has given to His Church a living Teaching Authority to elucidate and explain what is contained in the deposit of faith only obscurely and implicitly. This deposit of faith our Divine Redeemer has given for authentic interpretation not to each of the faithful, not even to theologians, but only to the Teaching Authority of the Church. But if the Church does exercise this function of teaching, as she often has through the centuries, either in the ordinary or extraordinary way, it is clear how false is a procedure which would attempt to explain what is clear by means of what is obscure. Indeed the very opposite procedure must be used. Hence Our Predecessor of immortal memory, Pius IX, teaching that the most noble office of theology is to show how a doctrine defined by the Church is contained in the sources of revelation, added these words, and with very good reason: “in that sense in which it has been defined by the Church.”
29. It is well known how highly the Church regards human reason, for it falls to reason to demonstrate with certainty the existence of God, personal and one; to prove beyond doubt from divine signs the very foundations of the Christian faith; to express properly the law which the Creator has imprinted in the hearts of men; and finally to attain to some notion, indeed a very fruitful notion, of mysteries. But reason can perform these functions safely and well, only when properly trained, that is, when imbued with that sound philosophy which has long been, as it were, a patrimony handed down by earlier Christian ages, and which moreover possesses an authority of even higher order, since the Teaching Authority of the Church, in the light of divine revelation itself, has weighed its fundamental tenets, which have been elaborated and defined little by little by men of great genius. For this philosophy, acknowledged and accepted by the Church, safeguards the genuine validity of human knowledge, the unshakable metaphysical principles of sufficient reason, causality, and finality, and finally the mind’s ability to attain certain and unchangeable truth.
30. Of course this philosophy deals with much that neither directly nor indirectly touches faith or morals, and which consequently the Church leaves to the free discussion of experts. But this does not hold for many other things, especially those principles and fundamental tenets to which We have just referred. However, even in these fundamental questions, we may clothe our philosophy in a more convenient and richer dress, make it more vigorous with a more effective terminology, divest it of certain scholastic aids found less useful, prudently enrich it with the fruits of progress of the human mind. But never may we overthrow it, or contaminate it with false principles, or regard it as a great, but obsolete, relic. For truth and its philosophic expression cannot change from day to day, least of all where there is question of self-evident principles of the human mind or of those propositions which are supported by the wisdom of the ages and by divine revelation. Whatever new truth the sincere human mind is able to find, certainly cannot be opposed to truth already acquired, since God, the highest Truth, has created and guides the human intellect, not that it may daily oppose new truths to rightly established ones, but rather that, having eliminated errors which may have crept in, it may build truth upon truth in the same order and structure that exist in reality, the source of truth. Let no Christian therefore, whether philosopher or theologian, embrace eagerly and lightly whatever novelty happens to be thought up from day to day, but rather let him weigh it with painstaking care and a balanced judgment, lest he lose or corrupt the truth he already has, with grave danger and damage to his faith.