Listen to Andrew Brody respond to my e-mail on his LSAT logic podcast entitled "Listener Logic #12. I sent it in just a few days before this podcast and was surprised at the quick turnaround, and honored that he gave my questions so much attention. People from all over the world listen to this podcast. It's quickly become my favorite podcast.
In my e-mail, I suggested that logic has major limitations in everyday life. I also had in mind the larger principle that autonomous logic without "help" from intuition ("higher logic") and ultimately value commitments, which are translogical, (like a commitment to the authority of revelation as in Christianity, Islam, and Judaism) leads to absurdity.
His response is interesting, as he agrees with me that autonomous "formal" logic is not sufficient, but his comment about "safe assumptions," leaves the ultimacy of what is or is not "logical" in the hands of relatively subjective intuition, which was my point in the first place. Our intuition (our "higher logic") must weigh in very heavily when it comes to making major decisions in life. For example, I believe that we all have a "knowledge of God" in our hearts (Rom 1:18-23), whether we are trained by formal logic to prove or disprove this knowledge. We all also have consciences that inform us about ethical decisions quite apart from statistics or formal reasoning. That's just the way God made us. Discernment can inform a decision when autonomous logic leads to a dead end.
Our ultimate presuppositions could fit into Brody's category of "safe assumptions," which brings us to the point--logic cannot be the ultimate authority. If it were, we couldn't prove the laws of logic to be objectively authoritative in the first place, because we would have to assume they were authoritative in order to do so, which is circular reasoning.
How do we know that logic leads to objectivity if someone in China makes up a different set of logical rules? Where do laws of logic come from? How can we know that they are objective, transcultural, and therefore capable of objectivity? Try to answer these questions without assuming logic, and you engage in circular reasoning. Try to answer even with logic, and statistics will prove nothing. Try to answer these questions from a broader "worldview" perspective, and you can makes sense of them.
If our logic is a development in evolution, then we have no reason to trust them as having been adapted to the human mind because they help us attain objective knowledge about the real world (Alvin Plantinga gives a highly sophisticated philosophical argument to make this point, entitled "Evolution vs. Atheism,"). If our logic is informed by revelation, we can ground logic objectively, since it's not man-made but God-implanted. In a Christian worldview, God made the logic of the human mind to assist us in obtaining real knowledge about the real world. He made our minds to perceive reality and reality to be perceived by our minds, and he made logic as our helper in the more sophisticated inquiry's of the world.