Rucker’s Mindscape

In his book Infinity and the Mind  (which you can read online at his website), Rudy Rucker puts forward the notion of what he calls the “Mindscape.”  He writes:

If three people see the same animal, we say the animal is real; what if three people see the same idea?

I think of consciousness as a point, an “eye,” that moves about in a sort of mental space.  All thoughts are already there in this multi-dimensional space, which we might as well call the Mindscape.  Our bodies move about in the physical space called the Universe; our consciousnesses move about in the mental space called the Mindscape.

Just as we all share the same Universe, we all share the same Mindscape.  For just as you can physically occupy the same position in the Universe that anyone else does, you can, in principle, mentally occupy the same state of mind or position in the Mindscape that anyone else does.  It is, of course, difficult to show someone exactly how to see things your way, but all of mankind’s cultural heritage attests that this is not impossible.

Just as a rock is already in the Universe, whether or not someone is handling it, an idea is already in the Mindscape, whether or not someone is thinking it.  A person who does mathematical research, writes stories, or meditates is an explorer of the Mindscape in much the same way that Armstrong, Livingstone, or Cousteau are explorers of the physical features of our Universe.  The rocks on the Moon were there before the lunar module landed; and all the possible thoughts are already out there in the Mindscape.

The mind of an individual would seem to be analogous to the room or to the neighborhood in which that person lives.  One is never in touch with the whole Universe through one’s physical perceptions, and it is doubtful whether one’s mind is ever able to fill the entire Mindscape.  (pp. 35-36)

When Rucker speaks of “thoughts” all preexisting in the Mindscape, he is evidently using the term the way Gottlob Frege does in his classic essay “The Thought,” viz. to refer to what contemporary philosophers prefer to call propositions.  (Though he also seems to have concepts in mind.)  A proposition is what is expressed by a declarative sentence, but is distinct from any sentence.  To take a stock example, the English sentence “Snow is white” expresses the proposition that snow is white, but that proposition is not identical to the sentence.  For one thing, the same proposition could be expressed instead in the German sentence “Schnee ist weiss.”  For another, the proposition would remain true even if no sentences in English, German, or any other language existed.  Notice, however, that the proposition would also remain true even if no human mind ever entertained it.  Propositions (or “thoughts” in Rucker’s and Frege’s sense) transcend not only language, but also any individual human mind or collection of human minds.  They are not to be confused with particular psychological episodes occurring in such minds.

They also transcend the material world, in Rucker’s account as in Frege’s.  Mathematical propositions would remain true even if no material world had ever existed.  Some propositions about the material world would remain true even if it went out of existence tomorrow (e.g. it would still be true that Caesar was assassinated on the Ides of March).  Even if there were no material world, so that the proposition that chairs exist was false, even that proposition would in some sense be real.  (By way of analogy, think of the way that a picture or sentence which misrepresents things still exists qua representation.)

For this reason, it is probably best to understand Rucker’s term “consciousness” in a loose sense.  At least much of what we think of as falling under the category of conscious experience has an essentially bodily character – pains and other sensations, visual and auditory experiences reflecting a specific point of view in time and space, etc.  If the Mindscape is distinct from the material world, then the aspect of the mind that accesses it does not do so by way of perceptual experiences tied to bodily organs like eyes, ears, and the like.  What Rucker regards as that which “moves” through the Mindscape is thus presumably the intellect, specifically, as opposed to the senses or the imagination (understood as that faculty whereby we form mental images of a visual, auditory, tactile, or other sort). 

The Mindscape, then, is essentially the collection of all the propositions and concepts that might possibly be grasped, entertained, affirmed, denied, etc.  The Pythagorean theorem would be an example of a denizen of the Mindscape.  When you entertain the theorem and I do not, you are accessing a part of the Mindscape that I am not, at least at that moment, accessing.  When we are both entertaining it, we are accessing the same part of the Mindscape.  But the theorem was there before either of us accessed it and will remain there long after we are gone.  The same is true of every other proposition or concept.  They are all out there waiting to be accessed, as it were. 

This is a very attractive idea, not only for metaphysical reasons – to which I will return in a moment – but also for moral reasons of a sort.  We are all familiar with the notion of the mind as a redoubt that even the jailer or torturer cannot reach.  “Do what you will to my body,” the prisoner might say to himself, “my soul remains my own.”  The comfort this provides can be pretty cold, though, if this refuge is thought of as a Cartesian prison.  The idea of the Mindscape makes of the mind a gateway to a whole other world, rather than a mere private cell into which one’s tormenter cannot trespass.  One can escape rather than simply hole up – escape into the very same world of thought to which every other mind has access.  This is perhaps what Winston Smith tries to reassure himself with when, in Orwell’s 1984, he meditates on the fact that 2 + 2 = 4 regardless of what the Party says or tortures him into saying. 

A natural way to interpret the Mindscape is as a Platonic “third realm” distinct not only from the material world but from any mind whatsoever.  Indeed, this seems to be more or less how Rucker understands it, just as it is more or less how Frege understood the “thoughts” he spoke of.  But there are other ways to interpret it.

Is a materialist interpretation possible?  It might seem that Jorge Luis Borges’ famous fantasy of “The Library of Babel” would provide a model for such an interpretation.  In this infinite library, every possible combination of the characters of an alphabet (at least within a certain page length) is said to exist in one of the library’s books.  It might seem, then, that any proposition or concept that exists in the Mindscape would have an analogue somewhere in Borges’ library.  Since the library and its books are material things, it might therefore seem that we essentially have the Mindscape in a physical form.

But this is an illusion, and the reason is not just that the Library of Babel doesn’t really exist.  Even if it did exist, it would not be relevantly like the Mindscape, and neither would any other material system made up of physical representations parallel to those in the library.  For one thing, many of the combinations of letters in books to be found in the library would be entirely random gibberish, expressing no proposition or concept at all.  There is nothing in the Mindscape comparable to that. 

To be sure, Borges tells us that none of the combinations of characters in the library would in fact be “absolute nonsense,” because there is always going to be some possible language in which a given combination conveys a meaning.  That is true, but it brings us to the deeper problem that the meaning of the combinations of symbols in any language, including that of Borges’ volumes, is entirely conventional.  That is to say, the symbols have meaning only insofar as we impart meaning to them, so that there must already be some independent realm of meanings we first grasp before imparting them to the symbols.  In effect, the Library of Babel presupposes the Mindscape, so that we cannot coherently reduce the Mindscape to the Library of Babel.  (Related to this is the problem that no physical symbol or system of symbols can have the sort of determinate or unambiguous content that a thought can have, so that a thought cannot be reduced to any set of physical symbols.  I have developed this line of argument in several places, most fully here.)

How about Karl Popper’s World 3 concept as a way to model Rucker’s Mindscape?  This is much closer to the mark, but still not quite right.  Popper thinks of the occupants of World 3 as man-made, whereas the occupants of the Mindscape pre-exist our discovery of them.  World 3 is a like a building we erect, whereas the Mindscape is a terrain we explore. 

A better alternative to the Platonic realist model is an Aristotelian realist one.  On this view, there is no “third realm” over and above the material world on the one hand and the mind on the other.  Still, the universal patterns and truths we grasp when we entertain concepts and propositions are neither reducible to any collection of material things nor mere constructs of the human mind.  The universal triangularity, for example, cannot be identified with any particular triangle or collection of triangles, and it is something we discover rather than make out of whole cloth.  However, rather than existing in a Platonic realm, it exists in actual triangles themselves, mixed together, as it were, with all their individualizing features.  Qua universal, it exists when an intellect abstracts it out of individual triangles by ignoring their diverse individualizing features and focusing its attention on what is common to all of them.

On this interpretation, the occupants of the Mindscape, though they are not reducible to or identifiable with anything in the material world, might nevertheless be thought of as embedded in the material world until the intellect pulls them out, as it were. 

The body of mathematical truths (which is Rucker’s special concern) is, however, a tricky one to fit into the Aristotelian realist scheme.  The reason is that the material world is finite and mathematics is concerned with infinities.  This brings us to a third brand of realism which claims to capture the strengths of both the Platonic and Aristotelian brands – namely, Scholastic realism.  For the Scholastic realist, Aristotle is correct to say that there is no third realm additional to the realms of matter and mind.  But Plato is correct to say that the ultimate ground of the truths and concepts we grasp must lie both beyond the material world and beyond finite minds.  It is to be located in the infinite, divine mind.  This is an idea that Scholastic thinkers like Aquinas inherited from Augustine, who in turn adapted it from the Neo-Platonic tradition.  (See chapter 3 of the forthcoming Five Proofs of the Existence of God for a detailed exposition and defense of Scholastic realism.)

How does Rucker’s Mindscape relate to Scholastic realism, then?  Here it seems there are at least two possible interpretations.  One might identify the Mindscape with the divine intellect.  On this interpretation, when the human mind explores the Mindscape, it is as if we are thinking God’s thoughts after him.  Or it is as if we are “streaming” content from the divine server, the way one might stream content from Netflix or Amazon on one’s computer. 

To the extent that this sort of idea is defensible at all, however, it would require thinking of the divine intellect more in Neo-Platonic terms than in strictly Scholastic terms.  For Neo-Platonism, the divine intellect is really a second divine hypostasis rather than God full stop.  It has to be, because God – the One – is absolutely simple or non-composite, and thus does not have within him anything like the distinctness that thoughts in a human intellect have.  Hence if the Mindscape is a divine intellect, it is something like the second divine hypostasis of Neo-Platonism, and not anything in God strictly speaking.  (Cf. the Averroist conception of the human intellect.)

Now, the Scholastic realist agrees that God is absolutely simple or non-composite.  But he rejects the notion of any second divine hypostasis a la Neo-Platonism.  Hence when universals, propositions, and the like are identified by the Scholastic realist with ideas in the divine mind, he means both that they are in God himself rather than in any secondary divine reality, but also that they are not in God in the manner in which the Neo-Platonist takes them to exist in a secondary divine hypostasis (viz. as distinct entities).

Here the Thomist doctrine of the analogical nature of theological language is indispensable.  When we say that universals and the like exist as ideas in the divine mind, we are not using “ideas” in either a univocal or equivocal way, but in an analogical way.  There is something in God that is analogous to our idea of triangularity, something in him analogous to our idea of the Pythagorean theorem, etc.  But it is not strictly the same sort of thing as our ideas.  (I’ve discussed the nature of the divine intellect in a couple of earlier posts, here and here, but see Five Proofs – which should be out in a matter of weeks – for a more thorough discussion.) 

The Mindscape, then, cannot be identified with the divine intellect as the Scholastic understands it, because the latter is simple or non-composite and the former is not.  But again, how then does the idea of the Mindscape relate to Scholastic realism?

The answer, I think, is that the Mindscape should after all be interpreted in more or less the Aristotelian realist terms discussed above, but with a qualification that brings in the distinction between metaphysics and epistemology.  Metaphysically speaking, universals, propositions, and the like are ultimately grounded in the infinite divine intellect rather than the finite material world.  But our knowledge of them is not acquired by directly accessing the divine intellect.  Rather, that knowledge is acquired by abstraction from the particular things of our experience, whose natures are reflections of the ideas pre-existing in the divine intellect.  The created world mediates our knowledge of God’s mind.

The Mindscape we know arises by way of this process of abstraction, and is a simulacrum of the divine Mindscape rather than identical with it.  Like any other simulacrum, it contains features which reflect, not the thing the simulacrum represents, but rather the nature of the simulacrum itself.  A black and white line drawing of a person may be extremely realistic and thereby convey much accurate information about its subject.  But the person himself is nevertheless not black-and-white, or two-dimensional, or surrounded by black lines the way that things in the image are.  Those features reflect the limits of the medium rather than the nature of the subject.  In the same way, the concepts and propositions to which we have access in the Mindscape reflect something which really is there in the divine intellect.  But the distinctness between the denizens of the Mindscape reflects the limitations of our own minds rather than the absolutely simple divine intellect itself.

Bonus link: Rucker’s essay “Memories of Kurt Gödel.”