Well the standards for a proper, valid, and lasting OP on TPF have to be fairly excellent as a bare minimum per the rules so let's not get carried away. Superfluous praise truly helps no one, certainly not the praisee.
Our beliefs are tested against the world, not against competing conceptual schemes. — Banno
This, while hard to refute as anything less than relevant, has a few points of contention I feel you'd agree are wholly reasonable to address. "The world", as many would perceive, is not truly "the world." It's how people have made society and thus an illusion of comparison to some sort of absolute everlasting state that both has been and would be without social engineering or otherwise, any other person living on it. One cannot truly "test their beliefs" against the "world" unless in an enclosed, isolated environment where either the individual (or group of like-minded individuals) are free to do so in an environment truly their own without any sort of influence or control by external factors. This cannot be done unless in some sort of socially and technologically barren or isolated landscape, which is virtually non-existent to the vast majority of persons.
We are social beings, meaning, to an extent, we're socially-engineered to be noticeably different or "set apart" from "the world" around us. Wherever people manage to thrive, that is solely because of artificial (or non-organic) creation of society and civilization. In short, society or groups of people and nations especially are in fact unique from "the world", per se. Each are furthermore in fact in competition, otherwise, armies and borders would not exist. So, there's basically nowhere on Earth you could go that is not socially engineered or given an artificial set of "what works vs. what doesn't" by those who live and place their identity under what eventually is little more than a competing social (ie. conceptual) scheme.
Basically, our beliefs "can", in theory, be tested against the "world", truly. It's not impossible. But realistically in 99% of cases never truly are, and simply are in fact tested against by what, by all irrefutable logical definition is in fact, a competing conceptual (specifically, social) scheme.
Let's say it's 1,000 years ago and you go to a never-visited island with a population of a few dozen people. That's you testing your beliefs against the world. But not really. Because they have made the region or reality you, in that moment, are confined to, as their own. No different than preaching the general belief in "equality" to a town of slave-owners. The "world", per se, has nothing to do with it. You're in a constructed society or region where the law, no matter how just or injust, is the only thing you're reasonably competing against ie. that provides resistance or response, at least, overshadows anything else by pure social will or force.
Ultimately, the only thing you're testing your beliefs against is that of others who have made a certain world, geography, region, or society, according to their conceptual belief, which by nature is in fact a competing one.
So, I disagree with the quoted statement above as some sort of 100% "happens all the time" absolute where a claim of the opposite would be, seemingly according to your wording, invalid.
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But in general, while I've never (to my recollection) read a word of the individual in question, giving the OP the benefit of the doubt and respect that he understands what the individual (Davidson) claims, and has the ability to recite it for us, I feel it appropriate to respond to that as one and the same.
In other words, I don't think I have to prove that spiders have experiences before I can tentatively believe that they're incommensurable to mine. Do I? — frank
This is interesting. What is the compelling or jarring factor that makes a spider different from one's own? Is it the size? The (so-called) scientific awareness of its ability (or lack thereof) to perceive the world (at least, in comparison to one's own)? Or something beyond? Surely one can imagine being kidnapped and placed in a hypothetical mansion where everything is say, equivalent to the difference in scale to the size of a spider vs. a human, perhaps 1000x the size of what a person is accustomed to? And then what? If we believe the spider has a conscious, a mind, a medium to process its surroundings to the point of a larger, more-intelligent picture, though perhaps not to the same degree, naturally, we have a reasonable avenue to contend the claim in one way or another. Otherwise, surely. It's just a spider, it doesn't know anything, it just "does". So which do we attest as more likely, and why?