"The Catholic Church never suits the particular mood of any age, because it was made for all ages. A Catholic knows that if the Church married the mood of any age in which it lived, it would be a widow in the next age. The mark of the true Church is that it will never get on well with the passing moods of the world."
- Venerable Fulton J. Sheen

Today, this quote, a critique of Modernism, is probably more applicable than ever. Both within the Church and in secular society we're used to hearing the retort "get with the times." A retort usually encountered whenever a traditional view is defended, all the more if it is currently unpopular.

To discuss Modernism we will first need to define it and then consider two of its consequences: rejection of Tradition, and the promotion of Liberalism.

In the same way that Antiquism would be a biased preference for the old things, Modernism holds a bias for the new things. The idea that because something is newer it must be better. It should not be difficult to see how such a bias is completely erroneous, and yet it's a very common bias in our modern times. This bias truly does derive from a Marxist view of history, whereby history can only be seen as a chain of improvements, where all changes that occurred are good, or at least they were for their time. But in reality, one could say that the Modernist doesn't truly understand even this principle, since it fails to see that, even throughout history, anything that was an improvement had to compete with and eradicate error. Just as today there may be some good ideas for changes that will improve our society, but they must compete with and eradicate those ideas that are erroneous. As such, not all new ideas are good ideas, but rather only some new ideas are good ideas and they must eradicate the bad ones.

Of course, even with such a philosophy that simply accepts some of the new things is still Modernism if it holds bias towards these new things over the old simply because they are new. This contrasts with Traditionalism, which builds a foundation of old things which over thousands of years have been shown rationally and practically to be beneficial, while adopting changes in form when necessary to better communicate the essence. Therefore, while Modernism and Traditionalism may not always contradict in those small areas where the Traditionalist sees it necessary to adopt newer forms, they will always contradict with the Traditionalist sees it necessary to maintain the older forms and (in particular) essence. In this regard, on matters of essence, the Modernist and the Traditionalist will always be at odds, for the Modernist holds nothing sacred while the Traditionalist holds essence to be sacred and immutable, as well as maintaining some forms that are truly more effective at conveying the essence, which Modernists do not defend in the first place. As such, Modernism is by its very nature contrary to Tradition.

But perhaps most sinister of all would be the element of Modernism's promotion of Liberalism, a nefarious ideology that deserves a criticism all of its own. However, here I am not referring to the modern conception of Liberalism, which is something vague and isn't always completely liberal in nature, but rather true Liberalism which is founded in the idea of the sovereignty of Man as both a individual and a political being from God; or as a much more well-formed man had put it:

"What naturalists or rationalists aim at in philosophy, that the supporters of liberalism, carrying out the principles laid down by naturalism, are attempting in the domain of morality and politics. The fundamental doctrine of rationalism is the supremacy of the human reason, which, refusing due submission to the divine and eternal reason, proclaims its own independence, and constitutes itself the supreme principle and source and judge of truth. Hence, these followers of liberalism deny the existence of any divine authority to which obedience is due, and proclaim that every man is the law to himself; from which arises that ethical system which they style independent morality, and which, under the guise of liberty, exonerates man from any obedience to the commands of God, and substitutes a boundless license."
- Pope Leo XIII, Libertas, The Holy See Official Website, p. 15

Seeing that God's mandates are eternal, for once and for always, this puts God and His law at direct odds with Modernism. God's laws are immutable, and as such they will never change. But this is not acceptable to the Modernist who adheres to change more than he adheres to God. As such, it is necessary for the Modernist to adopt Liberalism, and therefore heresy.

Modernism is not an acceptable or rational philosophy, as it defies reason, historical human experience, and God Himself in agreement with reason. As such, it is a philosophy that must be wholly rejected and repudiated.