Earlier quoted context omitted.
But the quote is only great on one level. If we give it some thought it is not so great. Why? Because our mind evolved as a tool for survival of our self which is to say as a tool for survival of that which may pass on the genes which create said mind. This mind is, by default, full of illusions, full of a particularly biased view of the world and the content of that view does not go away when we stop believing in it…
"In short the statement is only true for the rather small subset of things that can be scientifically investigated" Which fundamental things cannot get scientifically investigated?
Actually, let me make a stronger statement than before: Even for scientific facts the statement is weak. If I stop believing that the world is round, then what does it mean that the „roundness“ will not go away? From my point of view it certainly goes away and the world _will be_ flat. In order to accept that it is, objectively, not flat I have to accept other information, often information that I do not check or verify myself.
But subjectively, if I really stop believing the world is round then for sure it will start to feel flat.
So this criterion is not a good one.
I think it only is useful in the world of „succeeding“. So for example I may believe that a vaccination is dangerous and as a consequence I may die if unvaccinated. This is an example of reality not going away. Or I may believe that I can pass a test without studying but then I don‘t and so that‘s reality, again.