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Theory of sense-perception

Theory of sense-perception. 
This brings us to the self-contradiction of current materialist theories of sense-perception. The currently normative theory of sense-perception, which has its roots in modern ‘Enlightenment’ philosophy – notably the philosophies of René Descartes, Thomas Hobbes, John Locke, and most destructively that of David Hume – presents the sense organs as channels between the material world and our minds. For instance, it is claimed that light from some physical object produces an electrical signal in the eye, which then travels to the brain, where a mental image is produced, which is what we actually see rather than the physical object itself. The following description, by the American National Eye Institute, of the supposed process is one example among very many of this doctrine:
“When light hits the retina (a light-sensitive layer of tissue at the back of the eye), special cells called photoreceptors turn the light into electrical signals. These electrical signals travel from the retina through the optic nerve to the brain. Then the brain turns the signals into the images you see.”[1]
Consider the enormity of the claim made here, with zero awareness of its profound implications and utter absurdity. If what we actually see are mental images of the world out there, rather than aspects of the external world itself, then what reliable proof have we that there are any physical sources to our mental images? The sense-organs and brain we claim to have are known to us only through sense-perception, and therefore must themselves, under that theory, be mere mental images. In that case, there is no basis at all – other than mere imagination – for claiming that there exists around us a physical world producing mental images in us. In which case, the given theory of sensory perception is self-contradictory, starting with a premise that it ends up effectively denying!
Think about that; reflect on it. Proponents of this ‘representative’ or ‘correspondence’ theory claim that external physical objects are known to us by way of internal mental images; yet they propose no way for us to know the external objects independently and so be able to judge the existence and accuracy of such representation[2]. No ‘correspondence’ between internal mental images and external physical objects can be established if we only have access to one side (the mental side) of the story. All our perceptions would then have to be considered ‘true’, or alternatively ‘false’. There would be no way to verify, by means of comparison and contrast, some perceptions as true and others as false. Such verification is only possible if we are indeed able to distinguish between mental phenomena and physical ones.
Bishop Berkeley[3] was the first ‘Enlightenment’ philosopher to realize the implication of the above stated claim about the course of sense-perception. This led him, unfortunately, to deny the existence of matter and to claim that only mind exists. He called this viewpoint ‘Immaterialism’; but a more positive name for it would be ‘Mentalism’. Berkeley was intelligent enough to see the absurdity of the representative theory; but he was not intelligent enough, it seems, to draw a better conclusion from the conundrum than that of Subjectivism and Idealism. Moreover, he did not realize that the distinction between mentality and materiality, or dream and non-dream, is only possible by way of contrast, if both exist and both are accessible to us; if only one of them exists and is accessible to us, it cannot properly be characterized as either mind or matter, dream or non-dream.
Berkeley’s insight effectively meant that all his experience was a massive ‘dream’. Being a religious thinker, he chose to acknowledge the existence of other people and place his mind and theirs in the single mind of God. In this view, life was indeed a dream, but it was God’s dream. But logically this was the wrong conclusion to draw. The right conclusion to draw was that of Solipsism, viz. that Berkeley was the only existing person, and his own mind was the sole mind in the (his) world, and all other supposed people, including a supposed God, and their minds, were mere contents of his dream. If you the reader exists, your conclusion should be that Berkeley and me, and everyone else around you, are mere figments of your imagination, mere contents of your dream, and that only you exist.
Although the inference of Solipsism strikes most of us as unbelievable, Berkeley’s insight that the proposed theory of sense perception, as not involving direct perception of physical objects, but only their indirect perception by way of mental objects, logically implies that all a human perceiver ever perceives is mental images, and never their alleged physical source, remains valid.
To this day, I have not come across any modern philosophers or scientists who realize (even at least as much as Berkeley did) the crazy self-contradiction inherent in the dominant ‘representative’ theory of sense-perception. The world ‘out there’ is still dogmatically assumed to be physical, even while at the same time it is paradoxically taken for granted that we only have access to mental images of it, i.e. only to an ‘inner’ world.
The mind-body chasm inherent in that viewpoint cannot, unfortunately, be mitigated by adductive logic, i.e. by claiming that the putative physical world, though not inferable with certainty from our exclusively mental experiences, can still be assumed hypothetically and considered as at least inductively confirmed and made somewhat probable by those mental experiences. Such an approach would not solve the logical problem but constitute pure speculation, impossible to ever verify scientifically; it would be methodologically dishonest, being effectively merely circular argument posing as credible reasoning.
The logical conundrum, the self-contradiction of claiming both that a physical world exists and that we cannot at all perceive it, but can only perceive mental images (allegedly of it or brought about by it), has to be addressed and solved first. We must find some way to acknowledge that we actually, directly, perceive (some of) the physical world. An inductive hypothesis is indeed needed; but only one leading to such conclusion would resolve the issue.
It should also be pointed out that those who advocate the said muddle-headed theory of sense-perception imagine that they thereby free themselves of the need to acknowledge and explicate the fact of consciousness, i.e. the sui generis relation between subject and object implied by every act of cognition (including their own). But this supposition is mere fantasy, because whether consciousness is of (i.e. related to) an external object or of an internal one, it is still the same event of consciousness – only its object changes. And therefore, still the same mysterious and (I daresay) nothing less than miraculous phenomenon, itself neither physical nor mental nor even spiritual, but something somehow linking the subject and any sort of object.
In other words, the said advocates think that, by claiming perception only occurs internally, exclusively during perception of mental objects (whether derived from alleged sensory processes or entirely formed in the mind), they simplify and solve the problem of cognition. But no, the cognitive fact of perception is as difficult to understand and explain in the mental domain as it is in the physical domain. Presenting ‘sensory’ perception as not perception of physical objects, but as a physical process resulting solely in mental perception, misses the point entirely, the central issue – which is the mystery of perception as such, whatever its object.
When one realizes the profound challenges that cognition (whether intuitive, perceptual, or conceptual), and indeed similarly volition and valuation, present science with, one clearly sees that all attempts to escape the problems by postulating simplistic solutions, either purely physical or purely mental scenarios, or inconsistent formulae involving both matter and mind, are bound to fail. It is important to realize that consciousness and will are irreducible primaries, whose scope includes both the physical and mental domains, and indeed the spiritual domain too.
Moreover, when we think of our ‘mind’s eye’ watching mental images (or by analogy, our ‘mind’s ear’ hearing mental sounds, and so on for other qualia), we are presenting mental images as projected on a screen in our heads (or by analogy, mental sounds as coming out of a loudspeaker in our heads, etc.). But this colloquial metaphor implies some person doing the watching or listening, etc. It would be absurd to speak of mental images or sounds without assuming a conscious Subject (a self, a soul) observing these mental objects. Similarly, imaginations, which are products of active reshuffling of memories, whether voluntary or involuntary, are only meaningful if someone is present as their spectator or auditor. We cannot speak of mental phenomena while denying an experiencing Subject (as some materialists try to do). Purely material things do not have the capacity to experience; at least, no such power of matter has been demonstrated to date.
Indeed, even the mere existence of images or sounds made of a ‘mental’ substance (which they must likewise admit, if only by implication) is a major challenge to purely materialist claims, albeit a lesser challenge than that posed by consciousness (and volition and valuation). The enlightenment notion of ‘ideas’, defined as mental contents or entities (and no doubt ultimately simplistically imagined as sorts of balls of mental fluff) is not compatible with the purely physicalist ontology currently regarded as exclusively scientific. These alleged entities (or events or whatever) are necessarily of a different substance from physical entities; or at least must be assumed to be so, until and unless they are one day proven through empirical and mathematical methods to be themselves truly physical.
Until such equation is positively demonstrated, we are logically bound to regard matter and mind as distinct substances or domains, which interact and have some common features but are not the same. Moreover, since they evidently interact, all known physical laws must be formulated with the frank caveat that mental (and indeed spiritual) phenomena have not yet been taken into consideration and included in these laws.
What is the way out of the fundamental and supremely important conundrum pointed out here? The only way to retain our belief in matter, and not become exclusive ‘mentalists’ like Berkeley, or continue dishonestly turning a blind eye to the above-described self-contradiction like today’s materialist philosophers and scientists, is to assume that what we really see (and more broadly, sense, and even what we eventually conceive), when we apparently see the material world, is indeed (parts or aspects of) the material world itself and not mere (alleged) images thereof, not necessarily all parts or aspects of it (of course) but at least some. Only this assumption can logically justify our belief in a material world, and at the same time in a mental world distinct from it.
We are able to judge our mental images (memories and imaginations) as realistic or not, because and only because we can compare and contrast them to actual physical objects of sense-perception. If we only had mental images, with nothing beyond them to compare or contrast them to, we could not evaluate their realism (as Berkeley well understood).
To achieve this positive doctrine, called objectivism or realism (which is quite distinct from and antithetical to Berkeley’s subjectivism and idealism, note well), we need to creatively rethink the process of perception and the role played in it by our sense-organs and brain. Courage and honesty are needed to face this very difficult problem and try and solve it convincingly. Ingenious empirical research programs aimed at understanding what role the senses really play in perception are badly needed. Note well: I ask the question, but I do not claim to know the answer to it. That the answer is to date not known does not mean that there is no question or that the question can be ignored. What is sure is that if the question is not asked, the answer will never be found.
We must assume perception of matter is direct, i.e. that we perceive matter itself and not mere mental images of it. This seems a very reasonable assumption, considering the immensity and richness of the world we perceive as surrounding us – the Sun, the Moon, the oceans, the fields and forests, the cities, the people and animals – all this, with all its manifold details, cannot be produced and stored in our little brains. Admittedly, as Descartes pointed out, we sometimes have very clear and scenic dreams; but these are temporary flashes, not comparable to our much broader, clearer, multi-sensory, more logical, and persistent awake experiences. Our brains are very powerful, but not that powerful.
We must assume that the sense-organs and brain do indeed play an important role in perception of physical phenomena; but their joint role is surely only to make possible somehow our direct perception of the external world. They are the keys that open the doors for us (the souls that are perceiving), giving us access to (perception of) the physical world embracing us. In this new theory, the incoming signal from the retina to the brain is not useless, but it does not have the primary function of creating an inner image for us to perceive. It only serves to ‘open the door’ to direct perception, though it accessorily creates a mental memory of what we perceive through that door for future use.
What we are perceiving, in such case, is something physical outside us, i.e. material sights, sounds, odors, tastes, touch-sensations, and bodily feelings. There may well be errors in such perceptions, but they would be errors of appreciation and interpretation rather than errors of information. We still need, in such context, to properly evaluate our direct perceptions through reason. This is routinely done by referring to other, earlier or later, perceptions; i.e. we do not judge our perceptions through some other information source, but through the very same information source over time. Then we use inductive logic to draw the most reliable conclusions possible from the totality of information at our disposal.
Science must of course find out how exactly this ‘opening of the doors’ to perception operates, in order to replace, finally and credibly, the current self-contradictory ‘representative’ theory of perception. Complex conclusive experiments need to be devised to settle the issue. Admittedly, the needed exact explanation of direct perception is not easy to conceive (at least, no one has to date conceived of one). It is a problem of the same order of difficulty as the constant velocity of light was at one time; and a genius like Einstein is needed to find a credible and convincing solution to it. But that direct perception is a fact is logically indubitable since the opposite hypothesis of indirect perception is (as already pointed out) self-contradictory, and Berkeley’s mentalist option is contrary to the way we commonly regard and conduct our affairs.
The theory that we directly perceive external objects (even if, of course, only parts or facets of them), and not merely mental representations of them, is the theory adopted by people of commonsense everywhere; only some intellectuals cognitively divorced from reality, sundry mystics, and very mentally deranged persons, think otherwise (thus creating the ‘mind-body dichotomy problem’). However, this commonsense theory is rightly characterized as ‘naïve realism’ if it is not combined with an appropriate phenomenological approach. It becomes truly ‘subtle realism’ only if and when we understand that it is a consistent construct based on, ordering, and thus explaining, the totality of phenomenal data (inner and outer) that we collectively face. It is through the methodology of adduction (formulating a theory and testing it, ensuring its compliance with logic and empirical appearances) that we validate the conversion of the phenomenological givens into a direct realist theory of perception. The result is inductively sure (better than all alternatives), even if not absolutely certain.
 

[1]              https://www.nei.nih.gov/learn-about-eye-health/healthy-vision/how-eyes-work
[2]              Note in passing that the Lockean distinction between primary and secondary qualities is, from my point of view, rather arbitrary. It presents some qualities as indeed in external objects (e.g. shape) and some as having mental origin (e.g. color); but it is hard to see how this doctrine rhymes with the ‘representative’ theory – that is, how we could possibly make such a distinction under the regime of that theory. In my view, a quality like color can well, without logical difficulty, be claimed as a real property of the external object as a whole without denying that this is expressed by means of different electromagnetic rays. That is a reasonable phenomenological and positivistic outlook.
[3]              George Berkeley (Ireland, 1685-1753), in An Essay Towards a New Theory of Vision (1709) and subsequent books. Long before Berkeley, perhaps some 1500 years before him, Mind-Only Buddhism (Yogachara) seems to have made somewhat similar claims, though in a much more complex manner.
 

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