The Analysis of Mind, Bertrand Russell [best desktop ebook reader .txt] 📗

an irregular appearance are therefore

twofold:

 

(1) The object which is appearing irregularly;

 

2) The intervening medium.

 

It should be observed that, while the conception of a regular

appearance is perfectly precise, the conception of an irregular

appearance is one capable of any degree of vagueness. When the

distorting influence of the medium is sufficiently great, the

resulting particular can no longer be regarded as an appearance

of an object, but must be treated on its own account. This

happens especially when the particular in question cannot be

traced back to one object, but is a blend of two or more. This

case is normal in perception: we see as one what the microscope

or telescope reveals to be many different objects. The notion of

perception is therefore not a precise one: we perceive things

more or less, but always with a very considerable amount of

vagueness and confusion.

 

In considering irregular appearances, there are certain very

natural mistakes which must be avoided. In order that a

particular may count as an irregular appearance of a certain

object, it is not necessary that it should bear any resemblance

to the regular appearances as regard its intrinsic qualities. All

that is necessary is that it should be derivable from the regular

appearances by the laws which express the distorting influence of

the medium. When it is so derivable, the particular in question

may be regarded as caused by the regular appearances, and

therefore by the object itself, together with the modifications

resulting from the medium. In other cases, the particular in

question may, in the same sense, be regarded as caused by several

objects together with the medium; in this case, it may be called

a confused appearance of several objects. If it happens to be in

a brain, it may be called a confused perception of these objects.

All actual perception is confused to a greater or less extent.

 

We can now interpret in terms of our theory the distinction

between those mental occurrences which are said to have an

external stimulus, and those which are said to be “centrally

excited,” i.e. to have no stimulus external to the brain. When a

mental occurrence can be regarded as an appearance of an object

external to the brain, however irregular, or even as a confused

appearance of several such objects, then we may regard it as

having for its stimulus the object or objects in question, or

their appearances at the sense-organ concerned. When, on the

other hand, a mental occurrence has not sufficient connection

with objects external to the brain to be regarded as an

appearance of such objects, then its physical causation (if any)

will have to be sought in the brain. In the former case it can be

called a perception; in the latter it cannot be so called. But

the distinction is one of degree, not of kind. Until this is

realized, no satisfactory theory of perception, sensation, or

imagination is possible.

 

LECTURE VIII. SENSATIONS AND IMAGES

 

The dualism of mind and matter, if we have been right so far,

cannot be allowed as metaphysically valid. Nevertheless, we seem

to find a certain dualism, perhaps not ultimate, within the world

as we observe it. The dualism is not primarily as to the stuff of

the world, but as to causal laws. On this subject we may again

quote William James. He points out that when, as we say, we

merely “imagine” things, there are no such effects as would ensue

if the things were what we call “real.” He takes the case of

imagining a fire

 

“I make for myself an experience of blazing fire; I place it near

my body; but it does not warm me in the least. I lay a stick upon

it and the stick either burns or remains green, as I please. I

call up water, and pour it on the fire, and absolutely no

difference ensues. I account for all such facts by calling this

whole train of experiences unreal, a mental train. Mental fire is

what won’t burn real sticks; mental water is what won’t

necessarily (though of course it may) put out even a mental

fire…. With ‘real’ objects, on the contrary, consequences

always accrue; and thus the real experiences get sifted from the

mental ones, the things from our thoughts of them, fanciful or

true, and precipitated together as the stable part of the whole

experience—chaos, under the name of the physical world.”*

 

* “Essays in Radical Empiricism,” pp. 32-3.

 

In this passage James speaks, by mere inadvertence, as though the

phenomena which he is describing as “mental” had NO effects. This

is, of course, not the case: they have their effects, just as

much as physical phenomena do, but their effects follow different

laws. For example, dreams, as Freud has shown, are just as much

subject to laws as are the motions of the planets. But the laws

are different: in a dream you may be transported from one place

to another in a moment, or one person may turn into another under

your eyes. Such differences compel you to distinguish the world

of dreams from the physical world.

 

If the two sorts of causal laws could be sharply distinguished,

we could call an occurrence “physical” when it obeys causal laws

appropriate to the physical world, and “mental” when it obeys

causal laws appropriate to the mental world. Since the mental

world and the physical world interact, there would be a boundary

between the two: there would be events which would have physical

causes and mental effects, while there would be others which

would have mental causes and physical effects. Those that have

physical causes and mental effects we should define as

“sensations.” Those that have mental causes and physical effects

might perhaps be identified with what we call voluntary

movements; but they do not concern us at present.

 

These definitions would have all the precision that could be

desired if the distinction between physical and psychological

causation were clear and sharp. As a matter of fact, however,

this distinction is, as yet, by no means sharp. It is possible

that, with fuller knowledge, it will be found to be no more

ultimate than the distinction between the laws of gases and the

laws of rigid bodies. It also suffers from the fact that an event

may be an effect of several causes according to several causal

laws we cannot, in general, point to anything unique as THE cause

of such-and-such an event. And finally it is by no means certain

that the peculiar causal laws which govern mental events are not

really physiological. The law of habit, which is one of the most

distinctive, may be fully explicable in terms of the

peculiarities of nervous tissue, and these peculiarities, in

turn, may be explicable by the laws of physics. It seems,

therefore, that we are driven to a different kind of definition.

It is for this reason that it was necessary to develop the

definition of perception. With this definition, we can define a

sensation as the non-mnemic elements in a perception.

 

When, following our definition, we try to decide what elements in

our experience are of the nature of sensations, we find more

difficulty than might have been expected. Prima facie, everything

is sensation that comes to us through the senses: the sights we

see, the sounds we hear, the smells we smell, and so on; also

such things as headache or the feeling of muscular strain. But in

actual fact so much interpretation, so much of habitual

correlation, is mixed with all such experiences, that the core of

pure sensation is only to be extracted by careful investigation.

To take a simple illustration: if you go to the theatre in your

own country, you seem to hear equally well in the stalls or the

dress circle; in either case you think you miss nothing. But if

you go in a foreign country where you have a fair knowledge of

the language, you will seem to have grown partially deaf, and you

will find it necessary to be much nearer the stage than you would

need to be in your own country. The reason is that, in hearing

our own language spoken, we quickly and unconsciously fill out

what we really hear with inferences to what the man must be

saying, and we never realize that we have not heard the words we

have merely inferred. In a foreign language, these inferences are

more difficult, and we are more dependent upon actual sensation.

If we found ourselves in a foreign world, where tables looked

like cushions and cushions like tables, we should similarly

discover how much of what we think we see is really inference.

Every fairly familiar sensation is to us a sign of the things

that usually go with it, and many of these things will seem to

form part of the sensation. I remember in the early days of

motor-cars being with a friend when a tyre burst with a loud

report. He thought it was a pistol, and supported his opinion by

maintaining that he had seen the flash. But of course there had

been no flash. Nowadays no one sees a flash when a tyre bursts.

 

In order, therefore, to arrive at what really is sensation in an

occurrence which, at first sight, seems to contain nothing else,

we have to pare away all that is due to habit or expectation or

interpretation. This is a matter for the psychologist, and by no

means an easy matter. For our purposes, it is not important to

determine what exactly is the sensational core in any case; it is

only important to notice that there certainly is a sensational

core, since habit, expectation and interpretation are diversely

aroused on diverse occasions, and the diversity is clearly due to

differences in what is presented to the senses. When you open

your newspaper in the morning, the actual sensations of seeing

the print form a very minute part of what goes on in you, but

they are the starting-point of all the rest, and it is through

them that the newspaper is a means of information or

mis-information. Thus, although it may be difficult to determine

what exactly is sensation in any given experience, it is clear

that there is sensation, unless, like Leibniz, we deny all action

of the outer world upon us.

 

Sensations are obviously the source of our knowledge of the

world, including our own body. It might seem natural to regard a

sensation as itself a cognition, and until lately I did so regard

it. When, say, I see a person I know coming towards me in the

street, it SEEMS as though the mere seeing were knowledge. It is

of course undeniable that knowledge comes THROUGH the seeing, but

I think it is a mistake to regard the mere seeing itself as

knowledge. If we are so to regard it, we must distinguish the

seeing from what is seen: we must say that, when we see a patch

of colour of a certain shape, the patch of colour is one thing

and our seeing of it is another. This view, however, demands the

admission of the subject, or act, in the sense discussed in our

first lecture. If there is a subject, it can have a relation to

the patch of colour, namely, the sort of relation which we might

call awareness. In that case the sensation, as a mental event,

will consist of awareness of the colour, while the colour itself

will remain wholly physical, and may be called the sense-datum,

to distinguish it from the sensation. The subject, however,

appears to be a logical fiction, like mathematical points and

instants. It is introduced, not because observation reveals it,

but because it is linguistically convenient and apparently

demanded by grammar. Nominal