The absolute truth
I spent a career telling university students that if they encountered someone who claimed to know “The Truth,” they should run in the opposite direction because what would follow was bound to be religious dogma or a schizophrenic rant based on an encounter with God—the kind of truth that could not be checked or verified or even questioned. The notion of absolute truth disappeared after Nietzsche announced that “God is dead” in 1882 and Einstein followed up with a “theory of relativity” in 1905. Marx’s claim that “religion was the opiate of the people” made it plain, at least for we egg heads who occupied the universities, that the Twentieth Century was going to have to get by without “The Truth.”The tree of knowledge
The problem I faced as a professor was that my job was to be the serpent in the garden, encouraging young people to take a bite out of the apple from the tree of knowledge (no, not that kind of Biblical, carnal knowledge, just ordinary knowing things). How could I claim to be passing on knowledge without at the same time claiming that what I was teaching was true? Luckily, for me, I taught literature which had already been described as “The lies which tell the truth.” This paradox allowed me to evade the issue of “The Truth” and even “the truth,” but the question still dogged me.The correspondence theory of truth
Every five-year-old knows the difference between the truth and a lie, but once you’ve got a university degree under your belt, chances are you’re not so sure anymore. The five-year-old knows that if Mom asks “did you eat the cookie?” and you’ve still got crumbs falling from your lips, the truth is “yes, I did” and the lie is everything else . . . Martians, the imaginary friend, the dog and plain old “nope.” This is known as the correspondence theory of truth, and it is the default theory, which means if you have never thought of this question before this is what you think. A statement is true if it corresponds to “reality.” Did I mention that right after Nietzsche killed God, Einstein killed reality?Relativity, skepticism and the absence of truth
The reason the correspondence theory of truth doesn’t really work is that for the last hundred years or so, since Einstein said “E=Mc2,” and physicists admitted they really don’t know what “matter” is, we’ve all been pretty uncertain about what is and isn’t reality. Actually, for as long as human beings have been able to record their thoughts on the question, we have been uncertain about the nature of reality. The Greek philosopher Pyrrho took his skepticism and disbelief in reality so far that, we are told, his disciples had to go before him moving objects out of his way so that he wouldn’t walk into them. Nowadays our disbelief in reality isn’t so much of the walking-into-walls variety, but our certainty that we are uncertain has become widespread. The problem is that this uncertainty gets translated into a vague belief that there is no truth or the idea that truth really doesn’t matter anymore. Truth, in the postmodern era, is the baby that has gotten thrown out with the bathwater.Coherent truth
However, in the absence of absolute, God’s honest truth, and corresponds-to-reality truth, what is left to us is an imperfect form of truth known as “coherent truth.” Something is true because it is coherent in relation to something else that is true because it is coherent in relation to something else that is true and so on. Truth prevails as long as there is no break in the chain, no spot where something believed true upon which other truths depend is proven false, then the chain of truth must be reconstructed. More frequently, as we follow the trail of coherent truths we arrive at a moment where we have to shrug and admit that we just don’t know. This moment and gesture (the shrug) are known in rhetoric as “an aporia.”Truth only applies when there is meaning
Why would I accept such a seemingly weak form of truth? In the first place, there is a limited category of things which we can call true or false. Wandering in the forest, you would never stop before a tree and declare “this tree is true!” Entering a room you would never find yourself saying “this chair is true.” We only apply the question of truth to things which have a meaning. Only when there is a meaning can we say that something is true or false. It is impossible to say that something is incoherent yet true.Heuristic truth
In fact, there is a form of truth, that some people would consider an even weaker form of truth, which I accept. I accept it as the only kind of truth that is available to us. It is called “heuristic truth.” “Heuristic” is a tricky, and even dangerous, word. It derives from the Greek for “find” or “discover.” Heuristic truth is the kind of truth we discover through trial and error, though dialogue, though logic, through deductive and inductive reasoning, from experience and evidence and examples, because, in the simplest of terms, it makes sense; it is coherent.
If you google the word “heuristic” you will find definitions like “temporary” or “a short cut” to the truth. Maybe, but human life and the history of our species are temporary relative to the time frame of our universe. “Short cuts” are all we have time for.