"the real and only reality" would be better stated as ~"the small finite set of realities" (basically, each "tribe's" trained "take" on a given situation)...but

"the real and only reality" would be better stated as ~"the small finite set of realities" (basically, each "tribe's" trained "take" on a given situation)...but even then, it is always possible to point out a trivial, causally unimportant object level difference such that one can miss the point. Whether it is possible to circumvent this remains to be seen. Science has demonstrated it can to some degree, but it only covers a portion of reality.