Pascendi Dominici Gregis §13

¹³ Hence it is quite impossible to maintain that they express absolute truth: for, in so far as they are symbols , they are the images of truth, and so must be adapted to the religious sentiment in its relation to man; and as instruments , they are the vehicles of truth, and must therefore in their turn be adapted to man in his relation to the religious sentiment. But the object of the religious sentiment , since it embraces that absolute , possesses an infinite variety of aspects of which now one, now another, may present itself. In like manner, he who believes may pass through different phases. Consequently, the formulae too, which we call dogmas, must be subject to these vicissitudes, and are, therefore, liable to change. Thus the way is open to the intrinsic evolution of dogma. An immense collection of sophisms this, that ruins and destroys all religion. Dogma is not only able, but ought to evolve and to be changed. This is strongly affirmed by the Modernists, and as clearly flows from their principles. For amongst the chief points of their teaching is this which they deduce from the principle of vital immanence ; that religious formulas, to be really religious and not merely theological speculations, ought to be living and to live the life of the religious sentiment. This is not to be understood in the sense that these formulas, especially if merely imaginative, were to be made for the religious sentiment; it has no more to do with their origin than with number or quality; what is necessary is that the religious sentiment, with some modification when necessary, should vitally assimilate them. In other words, it is necessary that the primitive formula be accepted and sanctioned by the heart; and similarly the subsequent work from which spring the secondary formulas must proceed under the guidance of the heart. Hence it comes that these formulas, to be living, should be, and should remain, adapted to the faith and to him who believes. Wherefore if for any reason this adaptation should cease to exist, they lose their first meaning and accordingly must be changed. And since the character and lot of dogmatic formulas is so precarious, there is no room for surprise that Modernists regard them so lightly and in such open disrespect. And so they audaciously charge the Church both with taking the wrong road from inability to distinguish the religious and moral sense of formulas from their surface meaning, and with clinging tenaciously and vainly to meaningless formulas whilst religion is allowed to go to ruin. Blind that they are, and leaders of the blind , inflated with a boastful science, they have reached that pitch of folly where they pervert the eternal concept of truth and the true nature of the religious sentiment; with that new system of theirs they are seen to be under the sway of a blind and unchecked passion for novelty, thinking not at all of finding some solid foundation of truth, but despising the holy and apostolic traditions, they embrace other vain, futile, uncertain doctrines, condemned by the Church, on which, in the height of their vanity, they think they can rest and maintain truth itself.