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But even if we do fail to understand ourselves, there need not be any Godelian
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"twist" behind it; it could be simply an accident of fate that our brains are too weak to
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understand themselves. Think of the lowly giraffe, for instance, whose brain is obviously
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far below the level required for self-understanding-yet it is remarkably similar to our own
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brain. In fact, the brains of giraffes, elephants, baboons-even the brains of tortoises or
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unknown beings who are far smarter than we are-probably all operate on basically the
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same set of principles. Giraffes may lie far below the threshold of intelligence necessary
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to understand how those principles fit together to produce the qualities of mind; humans
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may lie closer to that threshold perhaps just barely below it, perhaps even above it. The
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point is that there may be no fundamental (i.e., Godelian) reason why those qualities are
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incomprehensible; they may be completely clear to more intelligent beings.
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Undecidability Is Inseparable from a High-Level Viewpoint
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Barring this pessimistic notion of the accidental inexplicability of the brain, what insights
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might Godel’s proof offer us about explanations of our minds/brains? Godel’s proof
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offers the notion that a high-level view of a system may contain explanatory power which
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simply is absent on the lower levels. By this I mean the following. Suppose someone
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gave you G, Godel’s undecidable string, as a string of TNT. Also suppose you knew
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nothing of Godel-numbering. The question you are supposed to answer is: "Why isn't
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this string a theorem of TNT?" Now you are used to such questions; for instance, if you
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had been asked that question about SO=0, you would have a ready explanation: "Its
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negation, ~S0=0, is a theorem ." This, together with your knowledge that TNT is
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consistent, provides an explanation of why the given string is a nontheorem. This is what
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I call an explanation "on the TNT-level". Notice how different it is from the explanation
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of why MU is not a theorem of the MlU-system: the former comes from the M-mode, the
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latter only from the I-mode.
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Now what about G? The TNT-level explanation which worked for 50=0 does not
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work for G, because - G is not a theorem. The person who has no overview of TNT will
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be baffled as to why he can't make G according to the rules, because as an arithmetical
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proposition, it apparently has nothing wrong with it. In fact, when G is turned into a
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universally quantified string, every instance gotten from G by substituting numerals for
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the variables can be derived. The only way to explain G's nontheoremhood is to discover
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the notion of Godel-numbering and view TNT on an entirely different level. It is not that
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it is just difficult and complicated to write out the explanation on the TNT-level; it is
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impossible. Such an explanation simply does not exist. There is, on the high level, a kind
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of explanatory power which simply is lacking, in principle, on the TNT-level. G's
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nontheoremhood is, so to speak, an intrinsically high-level fact. It is my suspicion that
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this is the case for all undecidable propositions; that is to say: every undecidable
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proposition is actually a Godel sentence, asserting its own nontheoremhood in some
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system via some code.
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Consciousness as an Intrinsically High-Level Phenomenon
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Looked at this way, Godel’s proof suggests-though by no means does it prove!-that there
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could be some high-level way of viewing the mind/brain, involving concepts which do
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not appear on lower levels, and that this level might have explanatory power that does not
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exist-not even in principle-on lower levels. It would mean that some facts could be
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explained on the high level quite easily, but not on lower levels at all. No matter how
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long and cumbersome a low-level statement were made, it would not explain the
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phenomena in question. It is the analogue to the fact that, if you make derivation after
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derivation in TNT, no matter how long and cumbersome you make them, you will never
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come up with one for G-despite the fact that on a higher level, you can see that G is true.
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What might such high-level concepts be? It has been proposed for eons, by
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various holistically or "soulistically" inclined scientists and humanists, that consciousness
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is a phenomenon that escapes explanation in terms of brain-components; so here is a
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candidate, at least. There is also the ever-puzzling notion of free will. So perhaps these
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qualities could be "emergent" in the sense of requiring explanations which cannot be
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furnished by the physiology alone. But it is important to realize that if we are being
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guided by Godel’s proof in making such bold hypotheses, we must carry the
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analogy through thoroughly. In particular, it is vital to recall tnat is s nontheoremhood
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does have an explanation-it is not a total mystery! The explanation- hinges on
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understanding not just one level at a time, but the way in which one level mirrors its
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metalevel, and the consequences of this mirroring. If our analogy is to hold, then,
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"emergent" phenomena would become explicable in terms of a relationship between,
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different levels in mental systems.,
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Strange Loops as the Crux of Consciousness
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My belief is that the explanations of "emergent" phenomena in our brains-for instance,
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ideas, hopes, images, analogies, and finally consciousness and free will-are based on a
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kind of Strange Loop, an interaction between levels in which the top level reaches back
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down towards the bottom level and influences it, while at the same time being itself
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determined by the bottom level. In other words, a self-reinforcing "resonance" between
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different levels-quite like the Henkin sentence which, by merely asserting its own
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provability, actually becomes provable. The self comes into being at the moment it has
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the power to reflect itself.
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This should not be taken as an antireductionist position. It just implies that a
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reductionistic explanation of a mind, in order to be comprehensible , must bring in "soft"
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concepts such as levels, mappings, and meanings. In principle, I have no doubt that a
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totally reductionistic but incomprehensible explanation of the brain exists; the problem is
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how to translate it into a language we ourselves can fathom. Surely we don't want a
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description in terms of positions and momenta of particles; we want a description which
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relates neural activity to "signals" (intermediate-level phenomena)-and which relates
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signals, in turn, to "symbols" and "subsystems", including the presumed-to-exist "self¬
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symbol". This act of translation from low-level physical hardware to high-level
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psychological software is analogous to the translation of number-theoretical statements
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into metamathematical statements. Recall that the level-crossing which takes place at this
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exact translation point is what creates Godel's incompleteness and the self-proving
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character of Henkin's sentence. I postulate that a similar level-crossing is what creates our
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nearly unanalyzable feelings of self.
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In order to deal with the full richness of the brain/mind system, we will have to be
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able to slip between levels comfortably. Moreover, we will have to admit various types of
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"causality": ways in which an event at one level of description can "cause" events at other
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levels to happen. Sometimes event A will be said to "cause" event B simply for the
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