[Note: This post was born out of a recent discussion on the always thoughtful and engaging OnePeterFive with fellow Catholic Murray. As my response grew too long to post in the discussion thread, I decided to place it here rather than clog up the board over there. -RC]
St. Pius X's Pascendi Dominici Gregis diagnoses Modernism as resting upon a two-sided foundation: Agnosticism and Vitalism. The first teaches that "human reason is confined entirely within the field of phenomena, that is to say, to things that are perceptible to the senses, and in the manner in which they are perceptible" and that, as a consequence, "it has no right and no power to transgress these limits;" the second teaches that "faith, which is the basis and the foundation of all religion, consists in a sentiment which originates from a need of the divine."
Everything in St. Pius' treatment of Modernism follows necessarily from this two-sided foundation, as he very ably demonstrates. The only deficiency I would ascribe to the great Saint's work - a lack which has not been supplied in the intervening century, as far as I can tell - is that of failing to make a sufficient inquiry into the motivation behind the adoption of that foundation on the part of the Modernists.
I contend that the adoption of that foundation was ultimately driven by the desire to insulate religious faith from the attacks of post-Enlightenment science. Before I am lambasted for sympathizing with the Modernists, let me explain:
Even a cursory examination of Kant, for example, reveals that the driving force in his huge body of work is the desire to make the core claims of religion and ethics as he understood them impervious to the attacks of the new science. His deep forays into epistemology and metaphysics, while they do represent attacks on Scholasticism, were actually the by-products of his searching for a more resilient foundation for religion, and to correctly understand the three Critiques one has to read them in reverse order. His true goal was to produce a rational proof for the existence of God and an objective foundation for morality which would be impervious to the attacks which had been launched against the classical-scholastic proofs since the days of Descartes. He pursued this goal relentlessly, and was willing to sacrifice anything in order to accomplish it - including that most fundamental and natural of all presuppositions, Epistemological Realism, i.e. the belief in the ability of man to know the world as it really is. Once he had loosed himself from this foundation, he was able to go about the work of setting up a new foundation which would lead inescapably to the end he desired.
I mention this because the failure of Catholic intellectuals to successfully combat German Idealism stemmed in large part from their failure to identify the motivation at work. Kant, for his part, was cast in the role of 'enemy of traditional metaphysics' - which he was, but by circumstance, not by design. As I said, his opposition to Scholasticism was not the product of animosity towards God or even the Schoolmen, but rather of the desire to circumvent what he saw as its weaknesses in defending a reasonable faith in God and the objective moral order. Attacking Kant as an infidel metaphysicist, which was the common reaction in Catholic circles, missed the point Kant was making: advances in science - both those made in his own day as well as those which he could see just over the horizon - possessed enough explosive force to threaten the very foundations of traditional Natural Theology and Morality, and if drastic measures were not taken, the whole edifice could come crashing down. The tragic irony here is, of course, that he himself became instrumental in the tearing down of the very edifice he sought to reinforce.
I see old-school Modernists - I do not refer to the present generation of apostates usually subsumed under that name, who are true revolutionaries - in much the same way, i.e. as men seeking to insulate their badly shaken faith by resorting to means which ultimately destroy more than they preserve. What is the Agnosticism of which St. Pius speaks if not the attempt to place the object of religious knowledge, e.g. God and His Revelation, beyond the destructive reach of science? Regarding this Agnosticism, he writes: "From this it is inferred that God can never be the direct object of science, and that, as regards history, He must not be considered as an historical subject." Indeed; but removing God from the field of scientific inquiry was not by design, but rather by apparent necessity: the Modernists let themselves become convinced that faith in God cannot be confirmed by science, and that the impartial study of history will conclude any investigation by finding no place for Him. As Laplace remarked to Napoleon, God had become "an unnecessary hypothesis." If, in order to accomplish this feat, the Modernist must deny man's ability to know objective reality, so be it. This leaves the field of subjective experience, upon which ground science has precious little authority, and the doctrine of Vital Immanence as the positive foundation for religion and morality is born.
I take no exception to St. Pius X's reaction to the Modernist threat of his day: the house was on fire and a heavy hand was needed to smother the flames. But he was unsuccessful in putting out the embers, which flared up again no later than with the reign of Pius XII, because nothing substantial had been done to transcend the now open antagonism between modern science and Sacred Scripture. As I discussed in a previous article (On the Interpretation of Sacred Scripture, or The Fissue of Pope Paul VI), the Popes from Pius IX to Benedict XV had undertaken dramatic measures to shore up the defences of traditional biblical exegesis against the attacks of modern science - all of which, however, was undone with the fateful publication of Divino Afflante Spiritu in 1943, which opened the crack through which the smoke of Satan, in the form of the previously condemned historical-critical method, entered the sanctuary and fanned the embers of Modernism into the raging inferno otherwise known as Vatican II. While new priests were swearing the famously defunct Oath Against Modernism, they were at the very same time eating away at the substance of the faith in God's Revelation - namely, the claim to objective reality - like "ecclesiastical termites," to borrow an arrow from Christopher Ferrara's quiver. Once the historical-critical method caught aflame, the Church Militant found itself theologically gutted.
And we have yet to transcend - I use the term judiciously - the conflict which has been raging for the better part of 500 years. The reason the defenders of scriptural authority have languished as they have is because they have failed to appreciate not merely the effect the Enlightenment has had on the thinking of modern man (for example, that he has been rendered effectively blind to what physicist and philosopher Wolfgang Smith refers to as "vertical causation", so crucial to a correct understanding of both theology and nature), but also the motivation behind those who have succumbed to its allure: the desire to defend their own faith - warped though it is - in God, Man and the Natural World. Any attempt to engage with Neo-Modernists of a more 'classical' bent - and they are everywhere today - must start from this position.