What is Truth?
Pilate said to Him, “What is truth?” (John 18:38)
In certain academic circles, it is unfashionable these days to speak of truth. At the beginning of the twenty-first century, we are supposed to be beyond the idea of truth, just as Nietzsche was supposed to have taken us Beyond Good and Evil at the beginning of the twentieth century.
The last five decades can be characterized as misusing the results of science and philosophy to leap to wild, unsupportable, metaphysical conclusions. For example, Einstein’s Theory of Relativity became, in the vernacular, everything’s relative, which was then internalized by many as truth does not exist. Most (if not all) people who claim to hold this view have never really thought about what it means and what the implications are.
Let’s look at the phrase: everything’s relative. The first question is: everything’s relative to what? Well, of course, everything is relative to everything else, which means that things can only be positioned in space and time relative to other things. But are ideas relative? For example, is beauty relative? Many people will shout yes! in answer to this question, but they do not realize that beauty is not relative, it is a matter of individual taste. These two concepts are not the same. For beauty to be relative in the sense of Relativity Theory, it would be necessary for a painting to be more or less beautiful depending on how fast I was moving through the room. This is not the usual meaning of the phrase beauty is relative.
Given that each of us has his or her own conception of beauty against which we measure everything for its level of ‘beautifulness’, does this make the concept of beauty relative? If each of us has an ideal concept of beauty to which we compare everything else, then beauty is not relative, it’s approximate. If one imagines a scoring system based on a ‘grade’ of zero to one hundred percent, then we could assign beauty values to everything based on the ideal of beauty, which would have a score of 100%. Of course, no actual thing could be perfectly beautiful (sorry Bruno Mars ), but the scores would be given out to things on a scale which slides upward toward perfect beauty without ever reaching it. The scores themselves could allow one to give a relative ranking of the beauty of various things (e.g., Notre Dame before the fire was twice as beautiful as the church down the street), but the rankings themselves are based on an absolute, and therefore are not “relative.”
This is the main idea behind Plato’s Theory of Forms ; he believed that there was an ideal version of everything, in which each individual thing participated to some extent. Therefore, although I am not tall, I still participate to some extent in the Platonic form of tallness; a professional basketball player participates even more in the form of tallness, but is, of course, not perfectly tall.
We now turn back to the concept of truth. If perfect truth exists, then all of our knowledge participates in this perfection to some (limited) extent. Objective truth exists, even if we can never be absolutely sure what it is. We can hope to continue an asymptotic assent toward truth however (see my post here).
It seems that, once this basic premise is accepted, the next step is to dismiss it from one’s conscious mind. Once consciously analyzed and accepted, there is little reason to reexamine it day-to-day. Why? As an analogy, say you replaced your kitchen floor, and you'd never replaced a floor before. The first few times you walk on it, you may test each step before walking on it with your full weight. However, within a few days you would just walk across your kitchen without giving it any notice – if not, you would drive yourself crazy. There are so many things we take for granted every day that, if we did not, we would have no mental energy to do anything.
Extending the floor analogy: Having a firm metaphysical base is a necessary first step to being able to move through life in a happy, harmonious manner.
One must, of course, be open to re-investigating these fundamental principles in the face of new information, lest we sink into an unthinking dogmatism.
 See for example Plato, Phaedo (links to Amazon)
 Bruno Mars, Just the way you are (links to Amazon)