For those who don’t know, there is a school of philosophy called, unfortunately enough given the passage of time, Modern Philosophy. It had several features, but the main one was that it denied that knowledge was really possible. It was rarely that explicit, and oddly enough started in the 1600s with René Descartes’ proof that knowledge is possible. It ended with Immanuel Kant’s work in the 1700s trying to come up with a workable substitute for knowledge. It’s a common school of philosophy, these days, and no one has ever been able to figure out how its adherents are acting in good faith—especially since its adherents deny that good faith is really possible—but everyone acts like they are anyway since they seem to claim to, and academia is a very polite place (in front of students, anyway). There’s a joke about Modern Philosophy which runs:
Modern Philosophy was born with Descartes, died with Kant, and has been roaming the halls of academia ever since like a zombie: eating brains but never getting any smarter for it.
The most pernicious effect of Modern Philosophy—and I say this despite Modern Philosophy’s causative relationship to the existence of Post-Modernism—is the version of knowledge which Kant came up with in order to try to solve the problems of Modern Philosophy. (In technical terms, Kantian epistemology.) What Kant proposed was, roughly, the following:
Kant went on to say that we must believe in God, free will, and the immortality of the soul, because the alternative hypotheses predict an irrational world, which is not what we live in.
Most everyone else who takes Modern Philosophy seriously was quite happy to believe that we live in an irrational world, and so they will happily reject all three. (Interestingly, Kant was reputed to be a creature of extreme habit that never varied; I don’t know if that was of any significance to his intuitions.) But this has become the dominant idea of what knowledge is. It is not a direct communion of the mind with things outside of the mind, which everyone up until this point had meant by knowledge whether they affirmed or denied it.
The tricky thing to recognizing this is that Kant was very intelligent, and of a philosophical disposition. Most people are not very intelligent, and more importantly most people are not of a philosophical disposition. The result, taking these two things into account, is analogous to what has happened in physics after Newtonian mechanics was shown to be false.
Someone unfamiliar with how physics is conducted might think that once Newton’s laws of motion were shown to be wrong, they would have been discarded, but they were not. The reason they were not is that they are not very far from correct in low-mass and low-velocity situations, but they are much easier to compute. Since most everything that happens on the earth is in a low-mass, low-velocity situation compared to where the errors in Newtonian mechanics become noticeable, people just go on using Newtonian mechanics whenever they know that the error would be small. Basically, they know that the laws are wrong, but since there is always measurement error and other sources of imprecision in practice, the laws can be used anywhere we know that the error would be so small as to be insignificant compared to our measurement tolerances.
People do the same thing with the theories of reality which they substitute for knowledge. Instead of, like Kant, coming up with one consistent theory which is the best theory they can possibly come up with, they will use several theories—which they know to be quite wrong in some cases—and just make sure to restrict their application of these theories to the parts of life where these theories produce correct results. (Also, emotional reaction is commonly used as the test of whether the theory is right—does the theory say something that makes people feel worse than the alternative.) Neck-down Darwinism is probably the best example. (If you’re not familiar with it: below the neck evolution explains everything about the human body, but above the neck all men are created equal.)
The result is that people are completely unfazed when you point out the contradictions in their beliefs. They already knew that their beliefs contradicted. They just have some sort of rule (possibly a rule-of-thumb) for which belief they apply in the cases of contradiction. Most of them take this as part of the nature of knowledge: since a universally correct theory is impossible (so far) to construct, the best that you can do is several contradictory universal theories which are only applied where they have been experimentally verified to produce “correct” results. Many people with Kantian epistemology consider it a sign of mental weakness to be unaware that your own beliefs contradict; only the small-minded or extremely inexperienced think that one theory covers everything.
The truly sinister thing about this epistemology is that it deprives the victim of the obvious means of escape. For most wrong theories of the universe, running into an unresolvable (actual, rather than apparent) contradiction is evidence that the theory is wrong, and a sign that alternatives must be sought. Someone suffering from Kantian epistemology won’t even pause at contradictions, so God alone knows how they will know to look for something better.