We recently ran across this term, were not familiar with it, and were curious about its derivation and anatomy. Unfortunately there's not much available in the typical sources. In 2001, Father Chad Rippinger, FSSP wrote a scholarly article in Latin Mass Magazine that touches on this philosophy and the deleterious effect that it had on the development and growth of the philosophy and belief in the wake of V.II of the rejection of ecclesiastical tradition. We thought you might like to read a little of this essay.
"(The) three sources of immanentism as they influenced the Church during the waning of an intellectual phase of Modernism in the 1950s and early 1960s provided the foundation for a psychological break from tradition as a norm. As Peter Bernardi observes, Blondel (Maurice Blondel, a French philosopher) was “working at a time when the Church was just beginning to become conscious of a certain break in its tradition.” The work of Blondel and the influx of the other modern philosophical points of view, which were antithetical to the ecclesiastical tradition, had a drastic impact on Vatican II. By the time Vatican II arrived, the intellectual foundation was in place for a systematic rejection of all aspects of ecclesiastical tradition.
Blondel and others, under the influence of modern philosophy, thought that modern man could not be satisfied with past ways of thinking. They provided an intellectual foundation upon which the Church, with a Council as a catalyst, could “update” itself or undergo an “aggiornamento.” With the foundations for the extrinsic tradition having been supplanted, the extrinsic tradition was lost. In other words, since the view of man had changed and since the view of the Deposit of Faith was subjected to a modern analysis, the extrinsic tradition, which rested upon these two, collapsed. We are currently living with the full-blown effects of that collapse. Catholics today have become fixated on the here and now, and in consequence the Church’s traditions have come to be treated not only as irrelevant but also as something to be distrusted and even, at times, demonized.
This has had several effects. The first is that those things that pertain to the extrinsic tradition and do not touch upon the intrinsic tradition are ignored. This manifests itself in the fact that some ecclesial documents today do not have any connection to the positions held by the Magisterium prior to the Second Vatican Council. For example, in the document of Vatican II on ecumenism, Unitatis Redintegratio, there is not a single mention of the two previous documents that deal with the ecumenical movement and other religions: Leo XIII’s Satis Cognitum and Pius XI’s Mortalium Animos. The approach to ecumenism and other religions in these documents is fundamentally different from the approach of the Vatican II document or Ut Unum Sint by Pope John Paul II. While the current Magisterium can change a teaching that falls under non-infallible ordinary magisterial teaching, nevertheless, when the Magisterium makes a judgment in these cases, it has an obligation due to the requirements of the moral virtue of prudence to show how the previous teaching was wrong or is now to be understood differently by discussing the two different teachings. However, this is not what has happened. The Magisterium since Vatican II often ignores previous documents which may appear to be in opposition to the current teaching, leaving the faithful to figure out how the two are compatible, such as in the cases of Mortalium Animos and Ut Unum Sint. This leads to confusion and infighting within the Church as well as the appearance of contradicting previous Church teaching without explanation or reasoned justification."