I wrote a good deal of this out last night, longhand. I will copy this over as a second draft, but keep in mind that I have a tendency to 1) be (what passes for <!-- s

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We're operating from different paradigms. I extrapolate from your focus on the idea of "truth" that you connect truth value directly with whether a paradigm is valid or not -- but of this I cannot be certain, because you haven't given me enough information.
My view is that the effects of a view are more important than whether the view is literally true or not. This is because in my view, truth IS reality itself. Not what is said about reality; not any theories we may hold about reality; not how we categorize reality. Our understanding is not equivalent to the real thing.
If reality IS truth, how people perceive reality is partial (as can be seen in our lack of ability to sense things such as radio waves, though we have proof that the effects of [what are presently conceptualized as] radio waves exist). Because we only perceive reality in the ways that our bodies have evolved to sense it, our ideas about the total of reality are in effect flawed from the beginning.
So, therefore, how people think about reality will (likely) never match the full view of actual reality. In a different lexicon, what I'm speaking about as "reality" is "objective reality"; however, an objective view of reality is extremely difficult to attain, to the point that I doubt if anyone has ever experienced it -- as a separate idea from gaining cognizance of the "ideal" of objective reality.
That is, subjective reality is accessible. A limited view of objective reality is accessible. A total view of objective reality, not so much. (At least, while embodied.)
My understanding of "truth" -- truth is reality. Language, art, religion, these are ways of attempting to gain order out of experience, so as to better understand it. However a person can order language so as to better mirror reality -- this is an attempt to mimic, in triggered thoughts, experience. (I do not mean here to refer to "triggered thoughts" as triggers exclusively for traumatic thoughts.) But, language in itself depends on shared meanings. Shared meanings depend on shared experience. I probably don't have to go into how experience is individual, and not shared...meaning that understandings are approximate, not exact.
When I say that what I'm talking about has to do primarily with pragmatics and not truth value -- I mean, for one thing, that I doubt anyone has hit on truth, yet -- by that I mean pure, accurate, unqualified truth which is a perfect mirror of reality. However, I do believe that we are
capable of
experiencing reality (insofar as our biology allows us to) -- just, not so much, understanding and communicating it. What I am not inclined to believe is that, at the very least, the average adult is in touch with this reality.
And right there, I'm probably drawing on Zen, though to what extent I'm actually Zen-influenced, is questionable. It is without doubt true that I do not accept the whole of the Buddhist paradigms that have been presented to me, though my thoughts do draw off of the concept of
upaya (as I know it) -- that something does not have to be literally true in order to be useful.
As I've established that I doubt that most of this talking-about-reality is actually true (though I also believe that it is the closest to truth that we can each come at this point in each of our subjective evolutions [barring for the moment the 'progressivist' idea of evolution in which that which comes later is seen as "better evolved" {it's blatantly not true}]); and I've established in a prior post that the places each of us are at, are wholly understandable in light of our past (and present) conditions, and that recognizing their understandability does not mean we should stagnate (this is called "compassion"); I've come to the point of realizing that even if our own understandings of our (subjective) realities and our lives disagree with each other, this is due to the nature of individual (or, as comes to mind to say, "alienated") experience.
Just because we disagree with each other does not mean all of our thoughts are invalid, or all thoughts except a certain set are invalid. Validity hinges on whether a paradigm accurately reflects the experience of the paradigm-holder, and leads to healthful growth and whatever goals that paradigm-holder has. In my case, peace and serenity are two of my goals. Certain paradigms I've held in the past, did not produce peace and serenity. I let them go, because they did not achieve my aims.
They were valid for me at a certain stage of my life -- that is, before I knew any better. But it was understandable that I did not know any better. I was, in reality, doing the best I could.
As the saying goes, "when you know better, you do better."
What makes a paradigm valid, if not truth? I tried to define this last night, and unfortunately for readers who want a concrete answer, I believe that what makes a paradigm valid will be different for each paradigm-holder to decide...
In my case, it's clear that I've been influenced by Buddhism, despite not currently being clearly Buddhist (we can get into how, some other time) -- my guidelines are that a paradigm, to be...useful...should reduce suffering for oneself and others; adaptive, in the sense that it allows the paradigm-holder to avoid unnecessary harm (including self-inflicted harm -- I realize that it is not always possible to avoid both self-inflicted harm and externally-sourced harm at the same time); it should be conducive to good health and both short- and long-term survival; and it should be compatible with the paradigm-holder's subjective reality.
If the paradigm is a tool, that tool should be of use. I am not sure it matters, if all of the above factors are fulfilled, whether the paradigm in question agrees with "objective" reality or not. But if it does not, and the paradigm is also not working in the way one intends (and one would hope that one would be conscious of one's intent in adopting a paradigm before adopting it!) one flaw becomes clear: the paradigm itself may not be well-adapted to reality. The less well-adapted it is, the less one can expect it to perform flawlessly in a given situation.
It is also possible for a paradigm's applicability to a given situation to change, either because the apparent situation itself changes (this often happens because the paradigm-holder just learns more about what was there all along), or because the paradigm-holder grows. There should, then, not be hesitation to utilize the ability to adapt, and shift to a paradigm that is better-suited to the circumstances.