I believe mlo’s point in following this line of thinking was to establish a baseline with whomever it was he started the conversion.
If you can agree that something can be true and actual outside of and apart from your validation of it, then the conversation can continue. If you don’t believe that, then there is nothing to build upon.
At least that’s my understand of where mlo was going with this.
I gave the examples of a thing existing, without proof and that they are realities(Pluto and Africa).
Shouldn’t the next step then be proof of the thing? or does the conversation stop at a thing exists because it exists?