Dear Florin,
I agree that one can imagine a recursive ontology. And if one has no sense of the real, then one might as well do so.
As I state in my essay, I sense gravity and I sense consciousness. I do not sense dozens of quantum fields nor do I sense a recursive computer.
Many people report states of consciously being "one with the universe". Last year a book, "My Stroke of Insight" described a neuro-anatomist's personal experience of a stroke, from which it took her eight years to recover. She, like many mystics throughout history, and many who have experienced LSD, report a 'merger' with the universe, as the mental boundaries dissolve. Several times in my life I have experienced this state of awareness, in which reality is experienced as a seamless perfect fluid with no boundaries, existing in the external NOW. It is not a state that is useful for achieving our daily tasks and surviving in a complex environment, but it is an ontological challenge of the first order. Therefore, I do not go in search of what I can imagine, rather I search for understanding of reality as I experience it. This seems to me to be the most ontologically productive approach. In the 1970s I developed computer design expertise to answer the question of how a robot (computer) can derive "laws of physics" from counters, adders, and logic. The computer does not 'understand' the laws, but it nevertheless derives them from observations. This approach, beginning only with physical hardware, and based on visual observations of dynamic systems, creates the 'description of behavior' that we know as the 'laws of physics'.
Next, I asked how, from a monistic, NOT a dualistic,universe these laws could come to be. My essay outlines the answer, based on thousands of pages of detail (referenced in the essay).
Having spent decades trying to 'figure out' consciousness, and giving others a chance to figure it out, I arrived at the conclusion that consciousness is an innate characteristic of the universe. It is NOT something that 'emerges' from structure. Math emerges from structure! Consciousness has been here since the beginning (and perhaps before?).
No one else has explained consciousness. FQXi member David Chalmers is close, in that he believes it is a 'dualistic' phenomena that exists essentially in parallel with the physical universe, but that is as far as he goes. He's quite famous for just going that far.
You state that no ontology is needed for having valid math theorems. I believe that you are basing that on your recursive proposal.
I reject all ideas based on multiple universes, multiple layers of recursion, multiple dimensions, etc. I've analyzed what I believe is the driving force behind these approaches elsewhere.
In my ontology ONE perfect universe that presents me, a local conscious maximum, with everything from particle physics to cosmology, with humanity in between, is so far beyond any 'multiple' idea that I wonder why people look there.
My sincere hope is that the failure to find the Higgs will make new physicists, those not yet so heavily invested in the Standard Model, look for an integral approach that makes sense. It exists.
Carl Sagan used to go on about 'big numbers'. Big numbers mean nothing to me. Unity and a unitary explanation are my holy grail. Another equation, another field, another particle, another dimension, another universe adds no value that I can see. There is originally ONE, and interacting with itself, there may come to exist a limit or dividing line that brings TWO into existence, and Peano's axiom takes care of the rest (figuratively speaking).
As for your comment that "reality is made out of relational structures", I agree, with the caveat that these derive from the unitary physical universe. But I do not agree that there is a dualism between reality and math, each completely describing the other. Math does not completely describe either awareness or free will. Math only describes the *interaction* of the consciousness field (awareness plus volition) with mass. Moving mass induces a circulation in the local consciousness field, and the local consciousness field exerts a Lorentz-like force on moving mass, as explained in my essay. But the conscious awareness and conscious volition (free will) are NOT completely described by mathematics, which is why Tegmark denied 'randomness' and ignored consciousness (with implied free will). Either destroys his basic premise.
Florin I read your essay twice or more in October and just printed it out to read again, because it is presently not clear to me why you must have the dualism in order to axiomatize physics. You may also wish to read the comments on my thread, some of which extend the remarks I've made above.
I very much enjoy this back and forth. Thanks,
Edwin Eugene Klingman