This chapter confronts certain ontological issues.

1.Empirical or Hypothetical.

2.Physical or Mental.

3.Concrete and Abstract.

4.Presentative or Representative.

1.Empirical or Hypothetical.

A basic principle of science is thatwe may rely on empirical evidence, and indeed that all our hypotheses must ultimately be grounded in experience.This means that we attach special credibility to the empirical, from which the credibility of the hypothetical is to be derived. The former is raw data, the latter involves processing of data.

This is all well and nice, but just what do we mean by ‘the empirical’, and how do we distinguish it from ‘the hypothetical’? The question is exceedingly difficult to answer with precision, as we shall see. For example, I may look out of my window, and see rain, but then discover that all I saw was a shower of water from the roof. The ‘rain’ seemed empirical enough at first, but then had to be declassified as a failed hypothesis.

In a large sense, anything appearing before us is ’empirical’ — it is in itself given, whether we interpret it correctly or not; in this sense, even the ‘hypothetical’ is empirical, and it is so even if misleading. In a narrower sense, not all appearances count as ’empirical’; those we label ‘hypothetical’ are either excluded from this heading, or only included under certain inductive conditions.

In any case, we cannot refer to the concepts of ‘reality’ and ‘illusion’ for the distinction, except after the fact. If we try to refer to divisions we commonly make, like the physical versus the mental, or the concrete versus the abstract, we still encounter difficulty. Still, these dichotomies play a role of sorts, so we should explore them in more detail.

We shall see that, ultimately, all phenomena arein themselvesempirical; the characterization of certain phenomena as hypothetical only arises insofar as they are taken asrepresentingsomething other than themselves.

2.Physical or Mental.

It is very difficult to define the difference between physical (or material) and mental (or imaginary) phenomena.

a.Most evident to us are what we call‘physical or material’phenomena. This at the outset includes the experience of sights, sounds, feelings, smells, and tastes, of various kinds and intensity (for example, sights vary in shape, color and intensity of light).

However, some of the sights, sounds, feelings, smells, and tastes we commonly experience, those in thinking or dreaming, for instances, somehow do not seem physical to us; so we call these‘mental or imaginary’phenomena, to differentiate them.

Thus, the various phenomena we primarily associate with the physical domain, are on second thought found not to be exclusive to that world, but also found in the mental domain. This means that we must refer to some other or additional factor(s), to define what we intend by the words ‘physical’ or ‘mental’.

b.In the field of physical phenomena, each of us experiences a group of phenomena as being peculiarly close to self: we call this our personal body.

Briefly put, within this body, we distinguish various organs, to which we assign different functions. Some of these organs, which we call the sense-organs, seem especially related to the above-mentioned physical qualities: the eyes to experience of sights, the ears to experience of sounds, and so forth; further scrutiny by biologists has shown us more precisely how each of these operates.

Our position at that stage is that phenomena like sights and sounds are physical if (seemingly) experienced ‘through’ the sense-organs, and otherwise they are mental. The body and sense-organs are themselves physical, being visible with our own eyes, audible to our own ears, and so forth.

c.Incidentally, we may now take note of another group of phenomena: the bodily pleasures and pains of different sorts, which we commonly experience.

These phenomena are not sights, sounds, smells, tastes, nor quite like other touch-feelings. Yet they seem to take place inside our personal body, in the head, heart, digestive tract, sex organs, members, and indeed further study by biologists has uncovered relevant sense-organs within the body.

Later, we consider that some of these bodily phenomena have physical causes, some mental causes. But their common location in the body establishes them as in themselves physical (specifically, physiological) phenomena, and we are led to expand the definition accordingly.

It is not clear to me whether the bodily pleasures and pains experienced during dreams, say, are occurring within the dream itself (i.e. are themselves dreamed), or are merely triggered in the physical body in conjunction with the dream. For this reason, I am not sure whether these feelings have mental equivalents, as the other physical phenomena do.

Note that modern biology, according to Curtis and Barnes (440-466), groups the sensory receptors as follows:

Like most animals we have mechanoreceptors (touch, hearing, position), chemoreceptors (taste and smell), photoreceptors (vision), temperature receptors, and receptors for the sensation we recognize as pain. We do not have electroreceptors or magnetoreceptors, but some animals do (458).

I do not know why pleasure is not mentioned here, incidentally[1]. In any case, the similarities of operation among some receptors does not imply that the sense-modalities, the phenomena apprehended by the perceiver, are qualitatively the same, note well.

d.We are tempted to define the physical domain with reference to space and time. The body and what lies beyond it seem extended in a continuum. However, this presents a difficulty, in that mental phenomena like thoughts and dreams are obviously also extended — certainly in time, and in a mental parallel of space, if not physical space.

With regard to time, we can say that physical phenomena are on the whole more persistent, and mental phenomena on the whole more ephemeral. However, this distinction is more statistical, than applicable to individual phenomena. Many physical phenomena are fleeting, and even those that are assumed permanent are not constantly experienced by us.

With regard to space, the issue is further complicated when we take into consideration various illusions:

Some physical illusions are explained with reference to physical causes other than the sense-organ through which they appeared. For example, optical illusions like the moon seeming in the lake due to reflection; we learn that the moon is not in the lake by diving in and trying to touch it. Other examples: an echo, or a lingering odor due to the continued presence of certain molecules in the nose.

Some physical illusions are explained with reference to the experienced or inferred malfunctions of the sense-organ through which they appeared. For example, if I cross my eyes and see double, or plug my ears and hear nothing. Or again, I see certain threads in front of my eyes, and assume they might be projections of scars in the lenses of my eyes.

Such physical illusions are judged unreal through alternative sense-organs, and relatively easy to explain. For instance, what I precisely see, when I seem to see the moon, say, is the light from the moon; there is always an extrapolation from the sensory interface. However, we thus learn that not all physical appearances are ‘real’ — some of the things which appear in physical space cannot be taken at face value, but must be regarded in a wider context. Such phenomena are said to bevirtual.

More difficult to understand, arehallucinations:

Some mental projections seem to occur ‘in the head’: as when I experience my verbal thoughts, or I close my eyes and visualize certain vague shapes or clearly remember the scene in a movie. Some mental projections are much larger and more vivid, but still seem to take place in an ‘inner space’: thus with strong dreams (we all occasionally have them), or in certain meditative experiences or prophetic visions, or under the influence of psychotropic drugs or of psychosis.

Butsome mental projections seem to go right out into physical space: through powerful memories, like a beloved face, or a frightening or disgusting animal we came across long ago; or again, in certain meditative experiences and prophetic visions, or through psychotropic drugs or psychosis.

Such phenomena, which we call hallucinations, are judged illusory by appeal to a wider context: because they are relatively intangible and fleeting, or by the verdict of one’s other sense-organs or other people’s, or with reference to their having been preceded by meditation or drug-ingestion. (There are, of course, many kinds of meditation.) However, as far as I know, they are not attributable to lingering or artificial impressions at the sense-receptors.

The fact remains that hallucinations seem to inhabit physical space although not regarded as physical phenomena. You can truthfully say of such an apparition: ‘it seems to be placed out there, to my left, between the table and the chair’ — even if it does seem unpalpable, and more transparent and transient (because these attributes are not exclusive to hallucinations). For these reasons, we cannot make a clear, spatial distinction between the physical and mental domains.

e.Another difference we might point to is that physical phenomena are public knowledge, whereas mental phenomena, however vivid, are private.

Not all the physical events which one experiences are also experienced by other people, but that kind of event is often agreed upon by two or more people.

In contrast (to my knowledge), mental phenomena are never, in that sense, shared. We can only report to others what we intimately see, hear, feel, smell or taste, and we presume others have more or less similar experiences under the same circumstances, but there is no way we know of to intimately test and confirm each other’s individual mental experiences simultaneously. Scientists can detect and measure their physiological accompaniments, but to date cannot ‘photograph’ figments of the imagination.

However, the reference to publicity or privacy does not provide us with a clear differentia. For a start, it involves a circularity: the anterior anti-solipsistic assumption that ‘other people’ are not themselves chimera, but as physical and conscious as they seem, and that our languages are coherent. Secondly, physical events are not invariably public, though we assume them to be potentially so, and perspectives differ anyway. Thirdly, even if you could see my fantasies and I yours, we would still (I daresay) agree that they somehow differ from physical events.[2]

f.In conclusion, all we can say to distinguish physical and mental phenomena is that they are, assumably, in some significant respect,‘substantially’ different — distinct stuffs.

The controversy as to which of the two domains is more ‘real’ than the other (some cultures favor the physical, some the mental), is not relevant to defining their difference. Whether this difference is profoundly radical; or the stuff of mental phenomena is only a peculiar kind of matter; or physical events are themselves but dreams — we do not know the answer to this question, and it is seen as not immensely important to philosophy once clearly posed. We can admit of a noticeable difference, without having to be able to explain it.

The two domains have, evidently, much in common: the experienced ‘qualities’ of sights, sounds, feelings, smells, and tastes. But our intuition tells us that they are somehow at odds; and a difference of some sort has to be assumed, because it helps us to resolve perceptual contradictions, such as (to take an extreme example) a hallucination being and not being in the same place as a table and chair. So we take it for granted.

Logic is quite able to deal with these issues in formal terms, through special kinds of conditionings, which may be called‘domain specification’propositions. We can thus say: ‘It physically appears that X is Y’, whereas ‘It mentally appears that X is not Y’. So conditioned, the statements ‘X is Y’ and ‘X is not Y’ may be both factually true and yet not in contradiction to each other.

A statement about physical appearance may be further delimited by specifying the sense organ(s) on which it is based. Likewise, a statement about mental appearance may be more precisely specified as an imagination in an awake state, or while asleep, or as a hallucination induced in such or such a way.

These forms are not new inventions, but are used in everyday practise. For examples: ‘I dreamed she had left me, but when I woke up I found her still there’ or ‘The surface seemed smooth (visually), but when I touched it I realized it was rough’.

Clearly, there is still a need for reconciliation of sorts, but it is not as pressing as it would be without domain specification. The reconciliation may consist in granting preponderance to one of the statements (for instance, awake experience is more credible than asleep), or making a compromise statement (for instance, the surface is smooth or rough to a limited degree).

3.Concrete and Abstract.

a.We experience the world as an enormous space, in which are a multiplicity of individual entities, which have a diversity of attributes and mutual relations; in time, these come or go, move, alter or remain, and interact, in innumerable ways. (This brief description makes no pretensions to completeness.) These things, be they real or illusory, are apparent. They are experiencedin boththe physical and mental domains. But what are they?

Concretely, all we can point to in either domain are individual phenomena like: blobs of green or blue, noises, odors, bitter-sweet, penetrability, texture, temperature — in short, the perceptible qualities. Everything else we ever discuss is‘abstract’.

The distinction of the concrete is its conspicuousness, it stands out; but the abstract is also somehow apparent, even though not manifestly so. The concrete as such seems more obvious, so we regard it as less open to discussion about how ‘real’ it is. The abstract as such is invisible, inaudible, you cannot touch it, smell it, taste it, it has in itself no perceptible quality — so we wonder how ‘real’ it is, if at all.

We all implicitly believe that the physical domain consists not only of concretes, but also and mostly of abstracts. Ironically, the concrete aspects of the physical domain are regarded by us as the least ‘real’ expressions of matter. Space, time, numbers, particles, waves, movements, forces, are all essentially abstract aspects.

Likewise, the mental domain is not limited to its perceptible qualities, but includes invisible, inaudible, and in no way perceptible, components. Furthermore, just as many of the physical domain’s concrete aspects have equivalents in the mental domain, so they have many abstract aspects in common.

b.Now, the questions arise, what are abstracts and how do we know them? If we cannot perceive them, can they be said to have any existence or reality, and how can they be in any way described or discussed?

Most people and many philosophers, focusing primarily on the material world, try to answer this question with reference to mental images. The abstract ‘squareness’ of concrete physical squares, they say, is a mental image we call up and match against them. However, this proposal does not solve the problem.

In the example given, all we are doing is comparing a concrete mental square to a concrete physical one: the abstract squareness they have in common, on the basis of which a match is made, remains unexplained. Furthermore, the example given is a relatively concrete one; the suggestion becomes irrelevant in more abstract cases. For examples, in ‘possession’ or ‘action’ or ‘force’ or ‘causality’ or ‘entropy’ or ‘relativity’ — there is not only no physical concrete to point to, there is no mental concrete to point to (though concrete and abstract factors may be allied).

Relegating physical abstracts to the mental domain is a useless exercise, for the simple reason that mental abstracts are equally imperceptible there. The problem is onlyonce removed, swept under the carpet, it is in no way solved. (The same argument can be made, incidentally, with regard to any other domain, like Plato’s transcendental world or Kant’s noumenal world.)

At this point we might be tempted to regard all abstracts as unreal, no more than meaningless words, for both the physical and mental domain. Some philosophers have attempted this.

But here again, logic intervenes. How can such a claim have any credence, if it consists of meaningless words. Either the statement is presented as meaningful and true, in which case it tacitly admits what it tries to deny, being filled with implicit references to abstracts, or the statement itself is meaningless and unrelated to reality, in which case how can we even consider it.

c.This leaves us with only one alternative. Namely, that some abstracts do really exist, even though they are imperceptible, and we are able to ‘experience’ them somehow, even though we do not know quite how. This position is logically tenable — it is relevant and consistent, unlike the other two.

We could still say that all abstracts are mental, but there would be no basis for such a discrimination. Once the experience of imperceptibles is accepted for the mental domain, there is no reason to exclude it in principle from the physical one. It would be an arbitrary complication, without specific justification.

I suggest, therefore, thatthere are abstracts in both the physical and mental domains, as we presume in common-sense. This means that abstracts are immanent within things; just other components of things, besides their concrete aspects, and as real as them.

This is not a claim that whatever abstract we assign to something is indeed there, but only an admission thatsomeabstracts are there and somehow known to be there. Some abstracts arenotthere, even though believed to be there. We cannot make sweeping generalizations either way.

With regard to thephysicaldomain, concretes are as a rule perceived through the senses. As for abstracts, some are known directly; they are on the surface of things together with their concrete aspects (e.g. the squareness of two squares). Other abstracts are known indirectly, and more fallibly, by imagination and inference from concretes and directly known abstracts (e.g. the chemical composition of water). Likewise, with regard to the mental domain, except that perception is inner.

4.Presentative or Representative.

An appearance may be merelypresentative, a phenomenon without pretensions (we say, ‘in itself’), or it may berepresentative, a phenomenon which seems to signify something beyond itself. In the former case, it is merely ‘an appearance’, in the latter, it is ‘an appearanceof‘ something. For example, a piece of paper is just that, whereas the words or drawings on it are intended to refer us to other things as well as just being what they are.

A daydream or dream, a psychic mood, a word or sentence uttered as mere sounds or written as mere shapes, taken in themselves, are just givens; they become questionable only provided we assign some interpretation to them.

We commonly err in judging a mental experience to be physical, or to ‘represent’ an unexperienced physical one; taken as they appear, these mental phenomena are empirical; what is hypothetical is their characterization as specifically physical. If we imagine a ‘talking horse’ without making claims that it does or can exist in the physical world, all we have is an ’empirical’ mental phenomenon; this phenomenon becomes ‘hypothetical’ only as soon as we propose, for instance, that it has an analogue in the physical domain.

Some of our ideas are formed by idle manipulations of images or words, in the way ofexperimentsto be tested. We try out new reshufflings of elements which were originally given in specific combinations, to find out whether these inventions also have or can be made to have a similar existence. Thus, for instance, we may wonder whether any ‘talking horses’ exist or can be genetically engineered.

Many of our ideas are formedby analogy. There is a use of analogy whenever we classify things together, under a vague impression that they are in some way alike, and assign them a common name. Often the argument by analogy consists in extrapolating some phenomenon from one domain to the other, or from some field within a domain to another.

Thus, for instance, whereas physical pleasure and pain are concretely manifest in the body, mental pleasure and pain are more elusively abstract; our idea of the latter may be formed by saying that they are ‘something like’ the former, ‘except in the mental instead of physical domain’. Likewise, psychological sickness may initially be merely an analogue of physiological sickness. Or again, I assume that other people’s minds are very similar to my own.

In some cases, we have doubts concerning some aspect(s) of empirical phenomena. Most phenomena seem to us to be clearly physical or mental. But some are not obviously the one or the other: an optical illusion or a hallucination may require an effort to categorize. The empirical force of concretes seems greater to us than that of abstracts. More broadly, some insights seem evident from the start; others require considerable work to convince us.

Taken neutrally, any impression we have, any idea that comes to mind, whether concrete or abstract, whether concerning the physical or mental domain, has the status of a presentation; it is in itself ’empirical’ (in the largest sense), the moment it but appears to our awareness. What qualifies it as ‘hypothetical’ (as against ’empirical’ in a more stringent sense) is any suggestion it might inherently be making (implicitly or explicitly), that it relates in a certain way to something else.

Although ‘hypotheticality’ always entails some mental construct, it is not the mental aspect, as such, of its existence which makes it ‘hypothetical’, but rather that it refers the mind from one thing to another. The act of hypothesizing is indeed mental; but the contents of the hypothesis may be physical or mental, concrete or abstract, whatever.

It is notwhatkind of thing we focus on, which determines our empiricism — but rather,howwe regard that thing. Whatever we perceive or conceive is always given and ‘real’, provided it is taken ‘in itself’. To the extent that we draw inferences from it, it is of course fallible. An inference may be true or false; it is true, to the extent that predictions fit the evidence, and false, to the extent that they fail to.

[1]Furthermore, I wonder if we are truly unable to perceive electromagnetic waves. I have rather often had the following experience: I spontaneously ‘hear’ a musical piece or song ‘inside my head’, then turn on the radio, and perhaps tune it, and discover that precisely that music or song is being aired. Coincidence? Or did I somehow ‘receive’ the radio program directly?

[2]An acquaintance of mine, Robert Fox, has pointed out to me, after reading the above remarks, that people seem to be able to have collective delusions, of a perceptual as well as conceptual kind; in such case, the irony is that someone without this delusion, or with a different one, would be the one judged ‘deluded’, because singular.