Humani Generis
24. Everyone sees how foreign all this is to the principles and norms of interpretation rightly fixed by our predecessors of happy memory, Leo XIII in his Encyclical "Providentissimus Deus," and Benedict XV in the Encyclical "Spiritus Paraclitus," as also by Ourselves in the Encyclical "Divino Afflante Spiritu."
25. It is not surprising that novelties of this kind have already borne their deadly fruit in almost all branches of theology. It is now doubted that human reason, without divine revelation and the help of divine grace, can, by arguments drawn from the created universe, prove the existence of a personal God; it is denied that the world had a beginning; it is argued that the creation of the world is necessary, since it proceeds from the necessary liberality of divine love; it is denied that God has eternal and infallible foreknowledge of the free actions of men—all this in contradiction to the decrees of the Vatican Council.[5]
26. Some also question whether angels are personal beings, and whether matter and spirit differ essentially. Others destroy the gratuity of the supernatural order, since God, they say, cannot create intellectual beings without ordering and calling them to the beatific vision. Nor is this all. Disregarding the Council of Trent, some pervert the very concept of original sin, along with the concept of sin in general as an offense against God, as well as the idea of satisfaction performed for us by Christ. Some even say that the doctrine of transubstantiation, based on an antiquated philosophic notion of substance, should be so modified that the real presence of Christ in the Holy Eucharist be reduced to a kind of symbolism, whereby the consecrated species would be merely efficacious signs of the spiritual presence of Christ and of His intimate union with the faithful members of His Mystical Body.
27. Some say they are not bound by the doctrine, explained in Our Encyclical Letter of a few years ago, and based on the Sources of Revelation, which teaches that the Mystical Body of Christ and the Roman Catholic Church are one and the same thing.[6] Some reduce to a meaningless formula the necessity of belonging to the true Church in order to gain eternal salvation. Others finally belittle the reasonable character of the credibility of Christian faith.
28. These and like errors, it is clear, have crept in among certain of Our sons who are deceived by imprudent zeal for souls or by false science. To them We are compelled with grief to repeat once again truths already well known, and to point out with solicitude clear errors and dangers of error.
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.[7] 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 an 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.
31. If one considers all this well, he will easily see why the Church demands that future priests be instructed in philosophy "according to the method, doctrine, and principles of the Angelic Doctor,"[8] since, as we well know from the experience of centuries, the method of Aquinas is singularly preeminent both of teaching students and for bringing truth to light; his doctrine is in harmony with Divine Revelation, and is most effective both for safeguarding the foundation of the faith and for reaping, safely and usefully, the fruits of sound progress.[9]
32. How deplorable it is then that this philosophy, received and honored by the Church, is scorned by some, who shamelessly call it outmoded in form and rationalistic, as they say, in its method of thought. They say that this philosophy upholds the erroneous notion that there can be a metaphysic that is absolutely true; whereas in fact, they say, reality, especially transcendent reality, cannot better be expressed than by disparate teachings, which mutually complete each other, although they are in a way mutually opposed. Our traditional philosophy, then, with its clear exposition and solution of questions, its accurate definition of terms, its clear-cut distinctions, can be, they concede, useful as a preparation for scholastic theology, a preparation quite in accord with medieval mentality; but this philosophy hardly offers a method of philosophizing suited to the needs of our modern culture. They allege, finally, that our perennial philosophy is only a philosophy of immutable essences, while the contemporary mind must look to the existence of things and to life, which is ever in flux. While scorning our philosophy, they extol other philosophies of all kinds, ancient and modern, oriental and occidental, by which they seem to imply that any kind of philosophy or theory, with a few additions and corrections if need be, can be reconciled with Catholic dogma. No Catholic can doubt how false this is, especially where there is question of those fictitious theories they call immanentism, or idealism or materialism, whether historic or dialectic, or even existentialism, whether atheistic or simply the type that denies the validity of the reason in the field of metaphysics.
33. Finally, they reproach this philosophy taught in our schools for regarding only the intellect in the process of cognition, while neglecting the function of the will and the emotions. This is simply not true. Never has Christian philosophy denied the usefulness and efficacy of good dispositions of soul for perceiving and embracing moral and religious truths. In fact, it has always taught that the lack of these dispositions of good will can be the reason why the intellect, influenced by the passions and evil inclinations, can be so obscured that it cannot see clearly. Indeed St. Thomas holds that the intellect can in some way perceive higher goods of the moral order, whether natural or supernatural, inasmuch as it experiences a certain "connaturality" with these goods, whether this "connaturality" be purely natural, or the result of grace;[10] and it is clear how much even this somewhat obscure perception can help the reason in its investigations. However it is one thing to admit the power of the dispositions of the will in helping reason to gain a more certain and firm knowledge of moral truths; it is quite another thing to say, as these innovators do, indiscriminately mingling cognition and act of will, that the appetitive and affective faculties have a certain power of understanding, and that man, since he cannot by using his reason decide with certainty what is true and is to be accepted, turns to his will, by which he freely chooses among opposite opinions.