Yes. 'truth is difficult to know even absent attempts to erect a barricade or to assert a monopoly.' Let me add that the barricades are not always erected innocently.
"The problem is you cannot get the two sides of this issue "together" in rational discourse"
Yes. Demanding 'a good will and a collaborative effort' (or maybe it could be termed a cooperative effort.
"Because people will not agree about what Truth "is," our society is divided and increasingly more disordered, with the result (for example) that in wartime, some significant fraction of the American people works for the benefit of an enemy that would destroy us in an instant, if they could but get the chance."
Yes. And, I must report to you that I do not expect this to change during the course of what's left of my lifetime.
"Truth is the source of the "good order" of the soul, and by extension of society -- and also of the universe itself"
I don't know why I'm saying (writing) anything here; I should just nod my head and let you keep talking. { 8^)
But I liked reading your comment here, and appreciate all your comments and the pings you send my way! So please keep on writing!
Me either, YHAOS. It seems to me we're too far gone in this direction, and though it might take some time to play out, humanity will reap what it has sown. It seems we're headed for another Dark Age.... We forget what befell Athens and Rome, and why; and so history will repeat itself I suppose.
Thank you for your kind words, YHAOS -- we see eye to eye on many, many things it appears. And thank you for writing.