If eyewitness testimony can be held to always be credible, then that calls into question wheater there can be such a thing as an illusion.
If eyewitness testimony can be held to never be credible, then that calls into question whether there can be anything but illusion. I'm sure that you will protest that you do not hold an opinion to that extreme. Yet your statement above indicates that you propose, indeed, to hold me to nothing less than that extreme an opinion. As I observed earlier, exaggerate and deny, deny, deny.
The "observer problem" persists depending on the vantage point..
What you(or I) see at some point is partial.. based on partial knowledge..
Unless you can "see/observe" the whole system even though valid, its partial..
Which makes the metaphor of the "body of christ".. even more significant..
Requireing many vantage points merged into one a "fuller vision"(more complete image) of reality..
It could take all of "us" to even see reality..