In this chapter, I want to specify some of the logical preconditions for any theory of knowledge. Some such criteria have of course been developed throughout the present treatise, here my concern is with issues relating to the role of the nervous system.

The intent is not to present a complete and definitive model of knowledge, but merely to demonstrate how a theory of cognition and memory must be tailored around certain fundamental insights of logic. Proposals falling short of these specifications may be rejected at the outset as without credibility.

1.The Immediacy of Sense-Perception.

2.Logical Conditions of Recognition.

3.Other Applications.

1.The Immediacy of Sense-Perception.

There is a very important first principle for all philosophy, all ontology, all epistemology, all science, supplied to us by logic. It is thatwe cannot consistently deny the ultimate objectivity of (some) knowledge.We cannot logically accept a theory of knowledge which in effect invalidates knowledge. (I personally learned this insight from Ayn Rand, though I seem to recall that she attributed it to Aristotle, in spirit at least.)

This means thatthe currently popular view that sense-perception is no more than a production of mental images — is logically untenable.Such a statement might at first sight seem ridiculous, since it denies something universally accepted as common sense, not only by most lay people, but even by some major philosophers and many scientists; however, bear with me, and we shall see its logic.

Ask anyone to express the work performed by our senses, and they are likely to reply: ‘light or sound or whatever impinges upon the corresponding sense-organ, and produces an electrochemical message, which is transmitted to the brain, where it is somehow translated into a mental image — which is what we in fact perceive in sense-perception (rather than the external physical phenomenon itself)’. To evaluate that position, we must make a distinction between its descriptive and interpretative aspects.

The description is given us by common experience and research by biologists. Sense-organs (from sense receptors to brain centers) play some crucial role in perception, since if they are blocked or damaged it is affected, and they have such and such a physiological configuration and manner of functioning. That is the empirically evident data underlying the above statement, and I am not contesting it.

On the other hand, the interpretative element is the belief that what we perceive, at the tail end of the described processes, are ‘mental images’, psychological phenomena which hopefully ‘resemble’ the original physical phenomena, produced in the brain somehow. This is a theory, which is open to question on purely logical grounds: if all what we perceive are ‘mental images’, then how can we know that these are imagesofanything, and even if they are, how can we know they in any wayresembletheir physical causes?

More specifically, our descriptive knowledge of the sense-organs and their processes, becomes no longer empirical but a mere postulate, which therefore cannot be used to confirm the theory. If our apparent perception of our body and the physical surrounds may itself only be a day-dream, as the theory suggests, it cannot be used as empirical evidence that there is a body surrounded by a physical world which together produce mental images.

Thus, though the theory in question begins with a presumption that there is a material world (including the sense-organs and external stimuli), it ends with a possibly contradictory logical conclusion that there may well not be such a world, preciselybecauseour knowledge of it is mediated by the senses. On the one hand, it views its data on the pathways of sensory messages asphysicalevidence for itself; on the other hand, it goes on to possibly deny the reality of such physical evidence.

Had we not begun with a presumption that there is a material world (radically distinct somehow from the immediately knowable mental world), there would have been no need to construct a theory relating certain perceptions to the sense-organs. All objects, whether mental or physical, including the sense organs, would be of the same, essentially fantasmic, stuff — and thus all equally directly knowable.

An issue only arises when we take for granted the common sense view that there is a physical (as against mental) world, from which the perceiver is separated by a body with sense-organs. This view is credible, since mental and physical phenomena do experientially seem to us somehow substantially different. It follows that the theory in question intrinsically presupposes (logically implies) that the descriptive data is specifically physical.

We thus have two modal hypothetical propositions in contradiction: ‘if the theory, then the data may not-be physical’ and ‘if the theory, then the data had-to be physical’. The antinomy involved is not of the form ‘if P, then nonP’, but of the form ‘if P, then both ‘possibly not Q and necessarily Q’, which implies ‘possibly {nonQ and Q}’. A theory which denies its own starting point has no logical standing.

The objects of sense-perceptions cannot be claimed to be mental images of otherwise inaccessible physical phenomena: because, if they areinaccessible, how can the proponents of that theory claim to haveaccessto them and know anything about them?

They cannot logically lay claim to any underlying physical events; and even if they do, what guarantee have they that the mental images perceived have anyresemblancewhatsoever to any presumed physical causes? An effect need not resemble its cause. Thus, it may well be that, say, the mental image of ‘green’ is invariably caused in everyone’s mind by a physical event of ‘square’: no one could tell. No claim of ‘truth’ could be made by anyone — not even by the proponents of that theory (it is intrinsically unconfirmable).

But in any case, there would be no justification in regarding perception of ‘externally generated’ mental images as in any wise more mysterious than perception of ‘inwardly produced’ mental images: all phenomena would have the same status. The subjectivity theory constructs redundant ‘duplications’, with the group of mental phenomena labeled ‘physical’ needing repetition as mental phenomena labeled ‘nonphysical’.

The problem has baffled philosophers, but I do not see why. If a position leads to paradox, logic demands that we simply reject it and find another. Here, although it is obvious that the apparent sense organsindeed must play a significant role of some sortin physical perceptions (since without them, it is lacking), the initial assumption that this role is production of mental images turns out to be inconsistent. Ergo, that assumption is nonsense, and some other explanation of the function of these organs must be sought.

To resolve the paradox, while maintaining that the data is indeed physical, we are logically forced to conclude that sense-perception (no matter what many people believe), is adirect, unmediatedrelation of consciousness, between the physical objects and the perceiver. We must accept that when we perceive an external object,it is the object itself and not some ‘representation’ of it that we in fact perceive. We must from the outset admit theobjectivityof sense-perception.

We must accept this primary logical requirement, and build our theory of knowledge around it. There is no escape from the logic. Thus, the light from a material object, its activity in the retina of the eye, the messages sent on to the brain — all these physically evident intermediaries of sight must be regarded asmere causal preliminaries, preparing us somehow for the actual act of seeing, which however is an unhindered Subject-Object relation. Likewise for the other senses.

(The computer provides us with an interesting analogy, though a partial one. The Subject keys in a statement he is reading on his table. The keyboard and CPU/Disk of the machine represent the sense-receptors and brain; the changes produced in the machine correspond to the nervous impulses and imprints; the partial display on-screen are analogous to mental images. But note well that the Subject sees both the external object and the on-screen copy if any, and is not himself to be confused with the machine.)

Philosophy is still left with the task of proposing alternative explanations for the role of the sense organs and their processes in physical perception. Starting with the admission of the common-sense view that there are physical, as distinct from mental, phenomena (including our bodies), manifold functions may be suggested offhand:

a.Some have recently suggested that the senses may serve tofilter outimpressionsother thanthe ones focused upon. It may well be that the senses produce a preliminary, relatively rough, mental image which allows us to decide whether we are sufficiently interested in the underlying object to awaken and invest a further effort of (more direct) consciousness towards it. Indeed, analysis of sensory messages seems to indicate that their content is relatively skeletal.

b.Perhaps the sense organs serve to somehow pin-point a consciousness which would otherwise be too general. It may be that the awareness of a disembodied soul would be too dilute to be effective in this world, like the state of mind called ‘enlightenment’ pursued by mystics. The senses may provide a material framework, a set of physiological conditions, in which an adequate ‘line of relation’ between perceiver and physical percept can be established, a ‘pipe’ though which a ray of consciousness can be sufficiently intensified.

c.It also seems likely that mental images are indeed simultaneously produced by sensory messages (always or often, automatically or by choice),as an incidental side-benefit, for purposes of future recall. Whether the sensory-messages produce both the nervous-imprint and the mental image, or (less likely) it is the actual perception which produces the mental image, independently of the nervous-imprint, I do not know.

These are just suggestions which come to mind; there may be better explanations. But in any case, the suggestion that the function of the senses is exclusively the production of mental images, which are all that we perceive, is logically unacceptable, and therefore wrong without a doubt.

Whatever the biological processes involved, then, at the moment of sensory perception (and, it seems to me, lingering on for a brief time thereafter, at least in some cases), the perception is direct. That the physical perception is thus direct, does not guarantee that it is complete, nor that it is pure of additional projections of an interpretative nature, note well. But if we are properly attentive, we can focus on the given exclusively.

An image may indeed incidentally be formed in the brain, for purposes of preliminary filtering and/or future recall. Such an image may be a clear and faithful mental ‘photograph’ (or ‘audiograph’ or whatever, as appropriate), or a vague and distortive one, but the initial perception relates to the object itself, not this image. This, to repeat, is a logical necessity.

It may be that we have some difficulty in accepting sensory perception as direct, because we tend nowadays to regard the soul as localized ‘in the head’, contiguous with the brain. This creates a physicaldistancebetween the perceiver and the things perceived, which are located at the other extremities of the sense organs. But it may well be that the soul is more extended than we assume, permeating the whole body; in that case, the issue of distance would be resolved.

With regard to introspective perceptions, they are generally of course accepted without question as irreducible primaries. This refers to concrete mental phenomena which are not, at the time they arise, stimulated by sensory stimuli, though they may well in the past have been, wholly or partly, given initial existence and form by sensory stimuli.

2.Logical Conditions of Recognition.

But the main function of the nervous impulses generated by sensation (and similarly for nervous impulses underlying intimate perception), is production of biological imprints which are necessary torecognition. Not mental images, note well, but codes of a physical (meaningnonmental) nature in the cells of the brain.

When we perceive two objectsat the same time, we can immediately ‘see’ (in the largest sense of intuitive insight) that they are ‘similar’ or ‘different’ in various respects. These direct comparisons may not at once reveal all the similarities and differences, and some of them may later be disagreed with and judged illusory — but in any case, these acts of consciousness are the primary building blocks of what we call ‘conception’.

Comparing simultaneous percepts seems simple enough, but what of comparison of percepts which areseparated by time? It is hard to say that in such case we ‘evoke’ a mental image of the past percept and match it with the present percept, because introspection shows that in most cases we are able to construct only a very imperfect analogue of the initial impression, if any.

Indeed, even as we call the image up, we know the imageitselfto be (usually) only a rough copy of the original direct percept, which implies that we are able to compare the present mental image to the past object by some meansother thanwith reference to a mental image. In other words, the image itself is liable to some judgment regarding its correctness.

It follows that our decision as to whether the perceptual object now facing us is or is not the same as some past manifestation, is not (or not exclusively) made through the intermediary of a stored mental image. How, then, are we able to‘recognize’anything, how can we claim that we have seen anything before?

This is a logical problem, as well as a more broadly epistemological one, in that logical science is based on the assumption that similarities and differences are recognizableacross time.

Our goal here is not to debunk human knowledge, for as we have seen such a reaction is logically untenable. Our goal is more humbly to determine the logical conditions for objectivity of knowledge. That knowledge is objective is indubitable, since the premise of subjectivity is self-contradictory. Two solutions to the problem may be proposed.

One, is to suppose that direct perception of past concrete objects is feasible; that long after an event is over, we may transcend time and space somehow, and sometimes ‘see’ it, the past event itself (not its present repetition or continuation), extra-sensorily. But this solution seems very far-fetched, even though not impossible to conceive. I have made attempts in that direction, but they are too speculative to include here.

Two, is to suppose that the distinguishable components of each concrete object (whether physical or mental) we perceive produce a certain‘nervous imprint’(let us call it) in the brain, which is substantially a physical (rather than mental) phenomenon of some sort. Such an ‘imprint’ may be a certain electrochemistry of the nervous cells — a molecular arrangement, a location or orientation of certain molecules, a specific combination of electrical charges — perhaps including a distinct synaptic network; whatever it is (it is for biologists to determine just what), we here predict it on logical grounds.

Thus,what happens in recognition is not comparison of the new percept, to the mental image of the old percept, but comparison of the nervous imprint of the new percept, to the nervous imprint of the old percept.If they match perfectly, the objects ‘seem’ identical; to the extent that the nervous imprints do not entirely fit each other, the objects are ‘experienced as’ dissimilar. This idea admits that not only sense-percepts produce imprints, but even mental images we construct voluntarily or otherwise may do so, note well.

In this way, even the mental image of an old percept can be judged as rough or accurate, according to whether the nervous imprint of the image is in all respects the same or only partly so, to the nervous imprint of the object it claims to reproduce. We may well suppose that the mental image is often a projection caused by the nervous imprint; this would explain why images which we normally find difficulty evoking clearly at will, may suddenly appear with force in dreams or under the influence of drugs, say.

The ‘matching’ of nervous imprints should not be viewed as a conscious comparison, but rather as asubliminalprocess whose end-product is a signal, directly perceived or intuited by the conscious Subject, that the objects in question, be they physical or mental phenomena, match to a greater or lesser degree. Note well, it is not the imprints themselves that we ‘see’, but some signal from them. Uncertainties may be explained by supposing that nervous imprints sometimes decay, or are lost; likewise, distorted memories may be due to deterioration of imprints.

In this way, past and present physical and/or mental objects are comparable. This theory frees us of the problems associated with the idea that mental images are the intermediaries of recognition across time. However, it contains logical difficulties of its own! What guarantee is there that an old nervous imprint has not been distorted, so that we ‘recognize’ a new object which is in fact unlike the old, or fail to ‘recognize’ a new object which is in fact like the old?

The only solution I can think of is ‘holistic’. To claim that such confusions invariably occur would be logically inconsistent, since such a statement (again) would be invalidating itself. Therefore, logic demands that at least some such comparisons have to be admitted to be correct. The question of ‘which?’ can only be answered by a broad consideration of all experience and logical insight.

That is, over time, if such errors have crept in, inconsistencies will eventually arise, which will signal to us that something, somewhere, went wrong, and we will accordingly modify our outlook in an attempt to resolve the contradictions. In other words, the experiences of similarity or difference are phenomenal, and are taken at face value until and unless otherwise proven, like all other experiences.

3.Other Applications.

a.Once we come to the realization that perception of physical objects (sensory perception) logically has to be as direct as perception of mental objects (intimate perception), it is much easier to accept the statement made in the previous chapter that conceptual insight also may be a direct Subject-Object relation, when its object is external as well as when its object is internal. Such immediate conception has been called intuition, in contrast to reflective conception.

The only difference between perception and conception is that the former is directed at concrete objects, and the latter at abstract objects. The only difference between sensory and intimate perception is that the former is directed at physical objects, and the latter at mental objects. A similar division can be made with regard to conceptual insight, whether intuitive or reflective, by reference to the physicality or mentality of the objects concerned. But in all these cases, the consciousness relation is one and the same phenomenon.

In conclusion, physical as well as mental concretes, as well as certain intuited abstracts, may be known directly and immediately. These, whether rooted in externally or internally directed acts of consciousness, serve as the raw givens of knowledge, and arein themselvesindubitable. However, beyond these ‘received’ primaries, most knowledge is constructive, and open to doubt and review.

By ‘constructive’ is meant, that concrete or abstract mental images may be reshuffled in any number of ways, forming innovative, hypothetical entities. The ‘building-blocks’ of such imagination are given from previous, ‘received’ concrete or abstract experiences; but these may be separated from each other and combined again together in new ways. Such fictions are often effected by manipulation of allied words (see ch. 4), but they may also be made wordlessly.

These constructs are to begin with imaginary, but some of them may eventually be supposed, with varying degrees of logical probability, to have equivalents which are not imaginary. Inductive work is of course required to confirm such suppositions. Fictions are of course not always deliberate imaginings for research purposes; they may be unintentional misperceptions or misconceptions, or only intended for entertainment or more obscure ends.

b.It should be obvious that what has in this text been referred to as a ‘nervous imprint’, is simply one of the senses of the word ‘memory’. I avoided that word, because it is variously used, also in senses which suggest renewed consciousness, or the reviewed objects, or actual images of previous objects — whereas I wanted to stress the subliminal aspect of memory, its material substratum.

Now, let us consider recognition more broadly. We suggested that when a percept (a concrete object of perception) is recognized, each of its many concrete attributes is encoded in the brain in some way, and matched against previous such nervous imprints.

Thus, there is supposedly a peculiar code for ‘red’, another for ‘hot’, and so forth, as well as for the various measures or degrees of such characteristics. We may similarly suppose that there is a special code for each of an object’s abstract attributes — that is, for each concept (abstract object of conception).

You may remember, we distinguished between two kinds of imagination: ‘perceptualization’, the projection of any concrete mental image, and ‘conceptualization’, the projection any abstract mental image. Whether such projections are voluntary or not, their recognition is effected in the same way.

Note well also that a mental image, whether concrete or abstract, may be recognized as resembling a physical phenomenon, in any respect other than the substantial one (obviously they will remain differentiated as mental and physical, respectively).

However, concrete and abstract phenomena, whatever their substance, cannot be equated to each other, though they may of course be in some way causally associated. In practise, of course, almost everything we consider is a mix of concrete and abstract components, so some comparison usually does occur.

Thus, recognition, in its widest sense, concerns any kind of object. Anything distinguishable in some way, be it physical or mental, concrete or abstract, is supposedly recognizable. Thus, recognition is ultimately recognition of what we call ‘universals’, the various components of things, which bundle together into what we call ‘particulars’ (more precisely, we mean ‘individuals’).

That is not to say that there is nothing more to a ‘universal’ than a distinct code, for the codes themselves are in fact just ‘individuals’ — but it is merely an observation as to what we may reasonably expect the nervous imprints, which we earlier posited, to correspond to. The point is that there is no essential difference between recognition of concretes and abstracts, be they physical or mental, however they were generated.