At the end of the 19th century the Church recognized that there was a growing movement (called “Modernism”) which held that all forms of truth were subject to change. In brief, the Modernists held that all truth of a doctrinal or moral nature was based on human feelings or intuitions; that the morality of divorce, for example, depended upon how people felt about divorce. Or, one God might be adequate for an isolated Christian society, but several gods might be necessary for a world society with open boundaries, by way of another example. “Truth,” at the moment, is determined by the consensus of the moment. (The Gallop Pollster is infallible, rather than the Pope!) For the Modernist, “truth” is ever evolving.
Modernism was condemned by Pope Pius IX in his “Syllabus of the principal errors of our time,” which is a catalog of the mistaken ideas of the Modernists. Its theoretical principles were more carefully explained and condemned again by Pope Saint Pius X in his encyclical Pascendi Dominici gregis, of September 8th 1907. Pius X also authorized a second syllabus of Modernist errors, called Lamentabili sane, and issued by the Holy Office on July 3rd, 1907. Saint Pius referred to Modernism as “the synthesis of all errors,” since it is not just one or more errors but an attack on truth itself. An “Oath against Modernism” was to be required of all men ordained to major orders, and of all those holding pastoral or teaching positions.
There are two errors that are related to Modernism, and which figure into the current problem. The first is a sort of pantheism taught by the Jesuit Pierre Teilhard de Chardin. Teilhard’s works were placed under a “monitum,” or “warning” by the Holy Office in the 1950s (in the 1910s he would have been shot!), but became very popular after Vatican II. They suggest that mankind is collectively evolving into god — I use the lower case “g” purposefully since Teilhard’s god is more of a cosmic consciousness or soul of the universe than the God we know. Teilhard had some impact on the Vatican II document Gaudium et spes on “The Church in the Modern World,” but I think his influence has diminished somewhat except in New Age circles.
A second error, related to Modernism (and Marxism) and very much with us is Existentialism. In traditional Catholic teaching, man’s purpose for existing is defined in terms of God: “Man was created to show forth God’s glory in this world and to share His happiness in the next.” Traditionally, man’s perfection is likewise measured in terms of God — how much did he know God, love God, and serve God? Existentialism, on the other hand, measures man in terms of man: Man is “authentic” insofar as he makes proper use of his “freedom.” Man’s perfection is measured in terms of human industry — how much did he build for mankind, learn for mankind, love for mankind, etc.? [Traditionally, man is what he is because he has an “essence” or “nature” established by God — existentialist man defines himself through his activities (see footnote 28).]
If you are with me so far, you will see that I have tried to give a thumbnail sketch of how the teaching authority of the Church is supposed to work, and how it relates to the immutable nature of truth. I am going to “change course” a bit now and list some of the major ways in which the new church has changed or subverted major articles of Catholic faith and morality. This is not an exhaustive list.