An Examination of Rationalism

Rene' Descartes

Rationalism is the principle that human reason is the only adequate measure of truth. The chief aim of Rationalism is war against the Supernatural, and insistence upon the claim that reason is the:

• Sole and absolute authority in the intellectual order.
• Final judge of action in the moral order.
• Ultimate court of appeal in the social order.
• Guide to happiness in the material order. 

To trace the origin of Rationalism fully would require far more space than I will commit here, but most will allow that it is the impetus behind Post-Modern culture and its operative mode of thinking-Relativism. The key to understanding Rationalism is to have a basic grasp of the salient principles of this school, and indicate the arguments which refute them. These three principles are:

1. Reason is the adequate measure of truth, and therefore autonomous.
2. Revelation is superfluous.
3. Reason in its development follows an upward course.

Is Reason Autonomous?

Absolutely not, since man depends on God for his existence and the exercise of his faculties.

The fact that Revelation has "de facto" been made, means reason is bound to accept it. 

Therefore, reason is not the only source of truth. Nor can the obligation of accepting revealed Truth be evaded by regarding it as a benefit which may be declined.

It is indeed a benefit, but also an act of Divine will which imposes obedience upon man.

Is Revelation Necessary?

For the prompt, certain, and general knowledge of natural truths, Revelation is morally necessary. Much more so when the truths either exceed the power of reason to attain, or where they concern the free decisions of the Divine Will, which can be known only by being communicated.

Does Reason Follow an Upward Course? 

We need to make a careful distinction here.

a) Relative to truths of the natural order Reason secures progress in two ways:

• negatively by removing error;
• positively by discovering new, and strengthening the hold on, old truths.

b) Relative to Supernatural truths there have been three dispensations: Patriarchal, Mosaic, and Christian, and the two former were perfectible objectively; not that they contained error, but in the sense that they were stages on the way.

c) Relative to Christian doctrine there is no possibility of objective progress. The whole Revelation was made once and for all. But there may be Subjective progress:

• Extensive-the development of the explicit from the implicit. For example, the doctrine of the two natures of Christ; 
• Intensive- the acquisition of clearer and more thorough knowledge of revealed Truth. 

Refutation

If the Rationalistic claim is regarded from the standpoints of History and Philosophy we see:

1. Reason doesn't tend naturally and necessarily to progress. The history of nations has been one of deterioration from monotheistic belief to the paganism of savage tribes, even if only in the secular sense. In the purely secular, reason has been used to justify such things as Eugenics, and other atrocities, which contribute nothing to upward progress.
2. Moreover, wonderful achievements of art in Painting, Sculpture, Architecture, and Poetry belong to the Medieval and Renaissance eras of Western Europe, and are objectively superior in their aesthetics to those which pass for such today.
3. Christianity is not the product of intellectual activity. It didn't emerge from the schools of Egypt, Greece, or Rome, but from an obscure corner of Judaea and from uneducated fishermen.
4. It is impossible to maintain that all religions, or all truth claims, are relatively true and legitimate. To hold such an opinion would be to violate the Law of Non-Contradiction. Truth is one and unchangeable. There can be no "my truth, your truth", but only THE Truth. If Rationalism were true in this assertion, then we would have no basis for deeming anything objectively evil, such as the Holocaust, since it was the "truth" of National Socialism, which they reasoned to, that such was permissible. Thus, Relativist claims are demonstrably fallacious.