“I suspect that most of the individuals who have religious faith are content with blind faith. They feel no obligation to understand what they believe. They may even wish not to have their beliefs disturbed by thought. But if God in whom they believe created them with intellectual and rational powers, that imposes upon them the duty to try to understand the creed of their religion. Not to do so is to verge on superstition.” —Mortimer J. Adler”Fix reason firmly in her seat, and call to her tribunal every fact, every opinion. Question with boldness even the existence of a god; because, if there be one, he must more approve the homage of reason, than that of blindfolded fear.” —Thomas Jefferson to Peter Carr, August 17, 1787

There are two reasons it is necessary to think systematically and in principles: An epistemological reason and a metaphysical reason.

The Epistemological Reason:

We need principles so we have a few fundamental beliefs we can handle and test…

The Metaphysical Reason:

Knowledge is ultimately based on reality. Reality is what we check our beliefs against…

But there is also a caveat:

While contradictions are to be avoided, sometimes one cannot avoid them, or does not know how to avoid them.

For example, the theory of relativity explains the universe on a large scale and the theory of quantum electrodynamics explains it on a subatomic scale. However, these two theories do not mesh. Because we are stuck, we realize our understanding is limited. We keep both theories because each has explanatory value in its own realm. However, one cannot believe a blatant contradiction. For example, how does one integrate the theory of evolution with the biblical account (as long as it is interpreted correctly). We do not yet know how to do it. Did God exist before the Big Bang or did he find after the Big Bang that he was most intelligent?