Summary: Lessons In Apologetics #2: Rationalism & Fideism
The next epistemological methodology is rationalism. Of rationalism, Geisler writes, "Rationalism is characterized by its stress on the innate a priori ability of human reason to know truth. Basically, rationalists hold that what is knowable or demonstrable by human reason is true (29)." To the rationalist, the mind takes precedence over experience and the information acquired through the senses as a foundation for truth and knowledge.
In a rationalist methodology, there exists in the mind a number of innate ideas or principles that allow the individual to arrive at an understanding of the universe. These include principles of logic such as the law of noncontradiction. It is from contemplation upon ideas generated through reflection upon such foundational principles that the thinker is able to postulate systems of truth in a manner reminiscent of mathematics and geometry.
For example, in his system, Descartes started from his "cogito, ergo, sum (I think, therefore I am)" as his ability to doubt was the one thing he could not doubt. From here, Descartes built a theistic proof.
Descartes begins this with the admission that, since he lacks knowledge, he is imperfect. However, to realize one is imperfect, one must have knowledge that perfection exists. Yet perfection cannot arise from within the imperfect. Therefore, there must be a perfect mind from which perfection originates and this is God (31).
An apologetic utilizing the rationalist approach possesses a number of strengths as well as drawbacks. As to its strengths, the rationalist method stresses a consistency of reality.
It follows that a rational God would create a universe that regularly operates in accord with verifiable laws that we as His creations would be able to arrive at through deliberative contemplation. As rationalists posit, the mind to an extent must possess some kind of mental architecture to process the jumble of sense experiences the individual is bombarded with almost constantly. Even Scripture indicates that part of man's knowledge regarding God and His character is innate as Romans says that even the Gentiles, who were not formally given the Law in the same direct manner as their Hebrew counterparts, still had many aspects of the Law written upon their hearts.
Despite the strengths of the rationalist approach to apologetics, the methodology is not without drawbacks. The foremost is the acknowledgement that it can be argued that the rationally consistent does not always translate into the realm of necessarily actual and does not provide the bedrock certainty its advocates claim. For example, regarding the ontological argument, Geisler notes, "But it is not logically necessary for a necessary Being to exist anymore than it is for a triangle to exist...But the point here is that there is no purely logical way to eliminate the 'if' (43)."
Of the next religious epistemology, fideism, Geisler writes, "In view of the fact that empiricism led to skepticism...and that rationalism cannot rationally demonstrate its first principles, fideism becomes a more reliable option in religious epistemology. Perhaps there is no rational or evidential way to establish Christianity (47)." Thus fideism holds that truth in religious matters rests on an accepting faith rather than a critical scrutiny.