Georges Quenot's objection claims that nothing exists when unconsidered, be it a mathematical structure or concrete singular objects to which it applies,It's more likely, I think, (or think I think at any rate), that EVERYTHING exists (in the sense of being an information-state
in a qubitstring multiverse, that is,) when unconsidered.
However, if that's so, it implies also that that sense of exist is unenlightening and trivial.
It is more interesting to ask: "What is observable (in principle)?", than "what exists?".
Perhaps a good weaking of "nothing exists when unconsidered" can be set up with a few alternative propositions:
1. "a thing must be of the kind that can be considered" (and thus must be informationally-consistent with the info-states
which exhibit observers) in order to be considered,
2. Some observers (like George) might prefer to reserve the word "exist" for "can (in principle) be considered", or even,
3. "Exist" is reserved for the stronger "IS being considered and therefore certainly can be considered (so exists for sure)."
I personally think it is a mistake to hold that only that which IS being observed exists. I think it behooves us to describe
general information-theoretic properties of the class of "things" that "can in principle be considered (or observed)."
Then reserve "exists" (or "can exist" i.e. potentially exists) for those type of "things".
Of course as you know I would decompose "thing" into "pattern of information-states".
So finally, I would rephrase my initial statement that EVERYTHING exists (even when unconsidered),
to say that "every information-state can be what it is, an information-state, regardless of whether it is observed (i.e.
communicated and represented)."
However to obtain a useful form of "exists" that allows a "doesn't exist", then we can take "exists or not" not to apply
to all information-states, but only to those sets or patterns of information-states whose form would make them
consistent with being communicated to and represented by observer patterns (SAS's). Note that some of these
"of-the-form-to-potentially-exist-in-the-same-universe-as-the-observer" information-states may still not occurr in
i.e. "not exist in" (or be unrealized in) the universe (set of "program executions") to which the observer (or class of observers)
Eric - was the circular definition invented before the wheel ? -