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.
Source: Humani Generis (Vatican.va)