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Shall the logic of contradictions be forestalled by verbally neutralizing paradoxical perceptions?

© Henry A. Flynt, Jr.

Set up three tanks of water, the left very warm, the center medium, the right cold.  (John Locke, An Essay Concerning Human Understanding, Book II, Chapter VIII, section 21.)  Put your two hands in the left and right tanks long enough to “adapt”/desensitize; then put both hands in the center tank, close to one another but not touching.  Your tactile senses will report the center tank to be cold and hot (to be a stickler, “colder” and “hotter”) at the same time.  It can be considered an experience of the logically impossible:  the same body, apprehended via one sensory modality, is found to have different temperatures at the same time (mutual exclusivity).  in fact, since the temperature differentials can be varied, you have what amounts to a two-valued “degree” that can be widened or narrowed continuously.

I may accept this as an experience of the logically impossible.  You have different (mutually exclusive) perceptions of a uniform body via a single modality at one time.  Judgments of relative temperature, when temperatures can be compared in sensation, are intuitive and standardized in everyday existence if the temperatures are moderate.

On the other hand, this case admits of being rejected as an experience of the logically impossible.  An assumed fact is involved:  a standing body of water has a uniform temperature.  This premise has lot of experience behind it, which is why it enters as experiential memory [Erfahrung] in making the judgment that the perception of divergent temperatures is anomalous.  However, the premise itself is not logically necessary.  One’s two hands are close, but do not occupy the same space.  We could assume that the reason why the two hands feel two different temperatures is that the standing body of water has different temperatures at locations a centimeter apart.  Then your hands are detecting the truth.  The “contradiction in experience” requires a thesis about the world, transcending the sensory evidence, in order to be a contradiction.

There is nothing intrinsically logically anomalous about feeling a different temperature in each hand.  It wouldn’t be a paradox if a very long iron rod were felt to be warmer at one end than the other.  The water-tank case is anomalous because the perception has as its context that the hands are sensing a body which “experience” (Erfarung) says cannot have stable temperature differences.  (We abstract from rigging the tank; cheating is not worth discussing.)  In short, that one’s two hands are reporting the same thing. [1]

if we accept this “neutralization” of “bothersome” evidence, then we forego a reasonable warrant for a new logic.  But I don’t want to miss out on a new logic.

I’m not objecting to keeping the bar for contradiction high.  The bar for contradiction should be kept high so that the new logic will not be a mere conceit.  I do not, for example, accept the viewing of Escher images as experiences of the logically impossible.  It’s a borderline case, because Escher incoherence can be drawn very tightly, as Graham Priest published in 1999.  Another case:  Tenney’s perpetual rising tone illusion.

If somebody neutralizes the water-tank evidence by reconstituting the verbal system on paper, that does not change my habits of recognition.  I still feel that what I sense is paradoxical.  It would take some further procedure to eliminate my intuition that temperature in standing water is supposed to be uniform (aside from special rigging). 

To offer a comment which will be more germane in the next section, if somebody doesn’t want the two temperatures to feel paradoxical, then hallucinatory psychic deformation is required.  To put it mildly, the subject has to be hypnotized.  What begins as a trick redefinition does not end there; it has to be completed with hallucinatory deformation.

If somebody insists on neutralizing the water-tank evidence as specified, we may wonder why they want to subject habits of recognition to selective reconstitution.  Is it because they are wedded to an ideology of realism and rationalism?  But in the case in question, the neutralization of the contradiction repudiates realism.  (You believe that the water is not as it is, but as you perceive it to be, cold on the left and hot on the right.)


The waterfall illusion affords an experience more urgent or more intimate than the tanks of water.  Cf. Tim Crane in Analysis, 1988.

Mutually exclusive apparitional contents are apprehended at the same time and place in one sensory channel, inducing us to describe the apprehension with an inconsistent phrase.  The experience is uncanny.  Pre-established verbal usage [intuitive and customary recognition of qualities] requires you to describe it with an inconsistent expression.  If that is not reason enough to model it as a contradiction, what would be?

What is at issue, here especially, is one’s acquisition of one’s native language in relation to sense-data—that is, one’s acts of recognition, which are of a habitual character.  (Another term for language-capture:  fixation.)  My experiential recognition-terms, like ‘red’ for a traffic light seen to be red and ‘green’ for a traffic light seen to be green. <Non-exhaustive exclusives.>  I am driving and I recognize the traffic light as red. 

The shared natural-language observational terms which I have acquired.  (My application of them in recognition has the force of habit.)  The labels through which I exercise recognition in experience.  They can be called descriptors here.

You could “discover” that red-proximate-to-green is different from red, and that red-proximate-to-green is identical to green.  Then red and green traffic lights are not mutually exclusive, and it is permitted to “go” on a red light.  You add a distinction which nobody wants in order to eliminate a distinction which everybody wants.  But the person I am writing for does not wish to drive in traffic if the other drivers have internalized that elimination. 

And:  it wouldn’t make all the people wrong who have assumed all these years that red-proximate-to-green and red are the same thing.  What it would mean is that you had dropped out of intuitive and customary recognition of entities, that you had dropped out of normative usage. [2]

To resume with an earlier remark, a trick redefinition, of itself, will not change your perceptions or habits.  Red will not look green because you call it green.  To eliminate fixated descriptors would require a hallucinatory psychic deformation—hypnosis, to put it mildly.  Then hypnosis becomes a method to create scientific truth.  Then my essay “Cognition and Denial” was very much to the point.

The question would be, to what purpose do you do this?  Not because you want to make it impossible for language to support mutual exclusiveness of qualities, surely.

One lesson is that we don’t find impassable barriers in the realm of the logic of descriptors.  There are cases like the counting stands or the waterfall illusion which are polar in the sense of being the most clear-cut.  Then we have intermediate cases, the three tanks and Escher figures.  The point is, what is the value of decimating your own intuitions to save an ideology?  It all cuts both ways.  If you neutralize every contradiction, you get a world without negation.  One could seek, by the indicated technique, to remove the contradiction from 1 = 2, so that we get a denatured, consistent 1 = 2.  But my readers don’t want that—precisely because their motive is to shore up conformism. 

A heavy-duty neutralization of contradictions does not save conformism as the conformist imagines.  If practiced across the board, it destroys conformism.  It unites what people want to keep separate.  It proves that a red traffic light and a green traffic light are the same thing because red-proximate-to-green can be distinguished from red and allowed to be identical to green.  My readers are not so hip, so advanced, that they want a neutralization of mutual exclusivity in perception which makes the drivers on the cross-street color-blind.


The “paradox”of the excess advance of the perihelion of Mercury

Physicists call the astronomical observation of the perihelion of Mercury a paradox.  That is quite misleading.  The observation is a neutral content; all they mean by calling it a paradox is that it disagrees with a tenet in classical dynamics.  Physicists have a system principle which says it can’t happen—and they recklessly call disagreement of a system principle with a present experiment a paradox.  

The astronomical observation of the perihelion of Mercury is not the presence of mutually exclusive contents at the same time and place in the same channel of detection.  Nothing forces us to articulate the observation with an inconsistent description. 

The Copernicus paradox is that we cannot say that the earth moves, because motion is defined as displacement relative to the earth.  It has been cited from physics as a paradox allowing neutralization.  But it is not germane to perceptual illusions.  It has to do with the coherence of theories, not perceptions and intuitions.  It has to do with the propositions of a theory, not with descriptors.  Abstract stipulations, not perceptions such that mutually exclusive contents are afforded in one channel.

But wait.  Science was not finished with the Copernicus paradox when it was neutralized.  It became a question of fact whether there is absolute motion.  In the twentieth century, scientists decided there isn’t.  At that point, Copernicus lost the argument; his claim that the earth is absolutely in motion was false because yet another system principle got discarded.

Again, nullifying inherited usage or stipulation is not so simple as pulling an escape hatch out of a hat.  The escape hatch turns out to be a swinging door.

In physics, it is a commonplace to abandon a system stipulation or system principle when a new observation contradicts it.  Physics continually “demotes” its so-called paradoxes because it continually discards the system principle contradicted by a new observation.  It is about readjustment of a symbolic system.  It is not the heavy-duty neutralization of contradictions.  The latter is as “dangerous” as the glorification of contradictions:  because people always have descriptors whose mutual exclusivity they want to maintain, because you don’t want a world in which nothing is mutually exclusive. 

Let me acknowledge that physics’ use of the term ‘paradox’ is not entirely reckless and gratuitous.  It all depends on where you want the emphasis to fall.  What we have is two propositions admitted in a system, which are in contradiction.  One is an observation.  The other is a dogmatic principle. 

The observation is not a paradox in itself, and it is misleading to say that it is.  But the physicist cannot simply affirm the observation and leave it at that.  There is no raw evidence in physics—because physics is not about my sensory existence, about spontaneous recognitions.  The observation has to fit into the context of principles—or it cannot count.  You cannot interpret a particle scattering experiment as a physical observation without referring to principles.  Otherwise it is merely a streaked photographic negative.


Two resolutions have been brought up in this discussion.

i) The so-called neutralization of paradoxes in physics, that is, abandoning a stipulation or other tenet found to be unproductive.  “Anything that lives in water is a fish.”  The “paradox” that whales live in water and have the physiology of animals.

ii) Lowering the bar to the extent that:  mutually exclusive apparitional contents which are apprehended at the same time and place in one sensory channel and induce us to report via an inconsistent phrase do not afford a contradiction. 

The cases are not the same and there is no reason to confound them.


Does the apparition called the waterfall illusion afford an experience of the logically impossible?—do we make a mistake by perceiving it <as contradictory>?

My answer in the first instance would be that the textbooks say the waterfall illusion affords an experience of the logically impossible, and that my intuitions agree with what the textbooks say.  I don’t need anything stronger than that to conclude that the waterfall illusion affords an experience of the logically impossible and may be modeled on that assumption.

I don’t want to reach for any more of a justification than this; to do so would be defensive.

To deny that the waterfall illusion affords an experience of the logically impossible indicts all the treatises in perceptual psychology as wrong.  But they can’t simply be wrong, because the issue is intuitive and customary recognition, that is to say, the normative relation of the natural language to sense-contents.  The textbook authors are the expert informants on the usage community to which they belong—standing on the shoulders of philosopher-psychologists going back to Aristotle.

Somebody might ask me to re-educate  my perceptions and intuitions to make a conclusion disappear because it is inconvenient for an ideology of realism and rationalism.  They would destroy any uncanny experience which deserves to be called an experience of the logically impossible—to support an ideology of realism and rationalism. 

[In fact, they would pull delusive psychic deformation, or hypnosis, out from under the rug and offer it as a technique of science.  We could apply the technique, and kill the perihelion of Mercury with trick redefinitions and hallucinatory psychic deformation.  Physics would never need a new theory, since we have a technique that kills all the raw evidence we don’t like.  The sword of redefinition and psychic deformation is two-edged; there is no reason why it should be allowed to cut in only one direction.
They would save realism and rationalism via that route?
What they teach us, embarrassingly, is that legitimate science is on a continuum with brainwashing.]

Their neutralization is dictated by a prior commitment to an ideology of realism and rationalism.  They extinguish raw evidence against this ideology.  They are prepared to re-educate their perceptions to support this ideology.  But why is this ideology preferred to the point that we must re-educate ourselves to make the raw evidence against it disappear?

Shall we raise the bar for contradiction across the board, until language cannot support negation?  The proposed neutralization is highly selective.  You don’t want to drive in traffic with people for whom red and green are not mutually exclusive.


Wittgenstein’s explanation of contradiction in the Tractatus.  Mutually exclusive things cannot be true for the same reason that you cannot see an area wholly colored with two colors.  When you see my counting stand, you could try to re-educate the logic of your intuitions so that you no longer call the sight of two colors filling the same area inconsistent.  But then you are disagreeing with a Wittgenstein principle.  Do conformists want to do that?


References, including schoolbook philosophers against elements of the logic of contradictions

Wilfrid Sellars, “Empiricism and Philosophy of Mind,” in Wilfrid Sellars, Science, Perception, and Reality B29.S49

Paul Feyerabend, “How to Be a Good Empiricist,” in Philosophy of Science, ed. M. Curd  Q175.P5129

Stephen Palmer, Vision Science QP475.P24

Tim Crane, “The Waterfall Illusion,” Analysis, 1988.

Graham Priest, “Perceiving Contradictions,” Australasian Journal of Philosophy, December 1999.

C. L. Hardin, Color for Philosophers B105.C455 H37

John Locke, An Essay Concerning Human Understanding, book II, chapter VIII, section 21, “three vessals of water”

[1] The English ‘experience’ has two meanings which German separates:  Erfahrung, learning; Erlebnis, sense-datum.

[2] It would mean that you rejected native speakers as the standard of competence.