There was a thread over in Liturgy and Sacraments on this basic subject, entitled, Have you read Pope Pius X’s Pascendi?
I, for one, think that modernism is a tremendous danger to the Church even now. Many of the problems that we have today can be directly attributed to this Modernism.
A response I gave in the thread cited above would be useful (at least I think it would be):
MODERNISM. A theory about the origin and nature of Christianity, first developed into a system by George Tyrrell (1861-1909), Lucien Laberthonnière (1860-1932), and Alfred Loisy (1857-1940). According to Modernism, religion is essentially a matter of experience, personal and collective. There is no objective revelation from God to the human race, on which Christianity is finally based, nor any reasonable grounds for credibility in the Christian faith, based on miracles or the testimony of history. Faith, therefore, is uniquely from within. In fact it is part of human nature, “a kind of motion of the heart,” hidden and unconscious. It is, in Modernist terms, a natural instinct belonging to the emotions, a “feeling for the divine” that cannot be expressed in words or doctrinal propositions, an attitude of spirit that all people have naturally but that some are more aware of having. Modernism was condemned by Pope St. Pius X in two formal documents, Lamentabili and Pascendi, both published in 1907. (Etym. Latin modernus, belonging to the present fashion.)
Modern Catholic Dictionary
There are to be found today, and in no small numbers, men, of whom the Apostle says that: “having itching ears, they will not endure sound doctrine: but according to their own desires they will heap up to themselves teachers, and will indeed turn away their hearing from the truth, but will be turned unto fables” (II Tim. iv. 34). Infatuated and carried away by a lofty idea of the human intellect, by which God’s good gift has certainly made incredible progress in the study of nature, confident in their own judgment, and contemptuous of the authority of the Church, they have reached such a degree of rashness as not to hesitate to measure by the standard of their own mind even the hidden things of God and all that God has revealed to men. Hence arose the monstrous errors of “Modernism,” which Our Predecessor rightly declared to be “the synthesis of all heresies,” and solemnly condemned. We hereby renew that condemnation in all its fulness, Venerable Brethren, and as the plague is not yet entirely stamped out, but lurks here and there in hidden places, We exhort all to be carefully here and there in hidden places, We exhort all to be carefully on their guard against any contagion of the evil, to which we may apply the words Job used in other circumstances: “It is a fire that devoureth even to destruction, and rooteth up all things that spring” (Job xxxi. 12). Nor do We merely desire that Catholics should shrink from the errors of Modernism, but also from the tendencies or what is called the spirit of Modernism. Those who are infected by that spirit develop a keen dislike for all that savours of antiquity and become eager searchers after novelties in everything: in the way in which they carry out religious functions, in the ruling of Catholic institutions, and even in private exercises of piety. Therefore it is Our will that the law of our forefathers should still be held sacred: “Let there be no innovation; keep to what has been handed down.” In matters of faith that must be inviolably adhered to as the law; it may however also serve as a guide even in matters subject to change, but even in such cases the rule would hold: “Old things, but in a new way.” - Benedict XV, Ad Beatissimi Apostolorum
Faithful to the task of strengthening his brethren in the faith, in confronting certain trends that were manifest in the theological context at the end of the 19th and the beginning of the 20th centuries, Pius X intervened decisively, condemning “Modernism” to protect the faithful from erroneous concepts and to foster a scientific examination of the Revelation consonant with the Tradition of the Church. - Benedict XVI, General Audience, 18 August 2010.
The idea of modernism has never been anything but utterly rejected by the Holy See. From another post in that thread:
Central to the idea of Modernism is the concept of vital immanence. Vital immanence is a concept where the quality of an action (belief, doctrine, etc.) begin and end with the life experience of the agent. That is all well and good, our life is shaped by our experiences and our perception of reality is going to be based upon our experiences.
The modernist takes this to the next step: not only do our perceptions begin and end with our life experiences, but the very nature of God and His revelation to us also change based upon that. In other words, they deny the transcendent truth of God – that the things He revealed to us as truths remain so regardless of where we are at.
In some circles, there is a belief in a Hermeneutic of Rupture (to borrow a phrase coined by or used by the Holy Father) as opposed to a Hermeneutic of Continuity. In other words, “Vatican II Changed All Of That.” The very notion that eternal truths would change with the life experiences of society utterly fits the definition of modernism.
That last paragraph is the biggest reason why I think modernism is a grave threat to the Church even today. We see so many times in the real world where Catholics are taught “Vatican II changed all of that”…sure, maybe not in so many words, but the implication is still there.