If there be Truth, then might we know it. So then might there be also such a thing as falsehood – as, i.e., failing to understand and agree with Truth: to know it. No Truth, no possibility of falsehood or error. All human cognition then presupposes that there is indeed Truth; for all of it proceeds according to decisions, to operations of assent or dissent, yes or no to this or that notion. All of it works to ascertain whether propositions are true, or are not. If there be no Truth, this operation cannot but be chaotic noise, through and through; noise, NB, that cannot coherently asseverate its own noisiness.
You can’t believe that you’ve erred unless you believe that you might have done otherwise. To think anything at all, then, is implicitly to presuppose the existence of the Truth.
“There is no Truth” falsifies itself. So is there Truth. And this has a number of interesting consequences. For, given Truth, so far then as we believe any falsehood, we are to that extent improperly ordered to what is Real. We are to that precise extent literally insane.
A false belief is manifest corporeally as a disorder of the central nervous system. It is a physiological illness.
False belief is a disease of the mind, and of its body.
Insanity is no problem until it becomes a problem. A false belief that is to our present circumstances inapposite is nowise going to conflict with anything that matters to us, will not have any opportunity to disorder our acts in respect to our concrete predicaments, and so will not discomfit those of us who are not too troubled by merely logical inconsistencies between credible propositions (regardless of their relevance to the practice of life as we now engage in it). I can, e.g., navigate by the stars whether or not I credit the Copernican hypothesis.
But in the limit – which is only to say, sooner or later – reality bites. All false beliefs eventually meet their comeuppance, in their conflict with life as lived. Not, to be sure, in the life of every mind that believes them, but in the society of such minds. Disagreement with the Copernican hypothesis is for those whose lives it concretely touches, such as astronomers and astronauts, an unwise act. So by extension is it somewhat unwise for the people who support and succor them, and depend upon their findings for their own: the rest of us.
Reality edits falsehood.
Or can; the preponderantly sane can learn from their errors. Offered a red pill, they take it; and then the scales begin to fall from before their eyes, one by one.
The preponderantly insane tend rather to double down on their commitments to their fantasies. They resist red pills with all their might. When mugged by events, they question reality, rather than their models. They cope with the mugging by casting about for someone they can blame for having perpetrated the mugging intentionally, and specifically against them. That way they can tell themselves that the mugging represented a willful distortion and abrogation of the specious world presented to them by their precious false models.
I have seen liberals of both sorts – preponderantly sane and preponderantly insane – since the election of Donald Trump to the Presidency. A few have begun to wonder, carefully, “what have I failed to understand?” Having realized that they have got something badly wrong, they have begun to wonder what else they might have missed.
Most have however responded to the cognitive dissonance between their ideas and the manifest reality of history by fleeing even deeper into their cherished delusions.
It’s a lousy tactic. Delusions are a poor basis for the coordination of acts. So the insane suffer adverse selection pressure. Reality edits falsehood.