Perception

341 Pages·1961·16.447 MB·English

by  H. H. Price

PERCEPTION
by
H. H. PRICE
Wykekam Professor of Logic in the University of Oxford
METHUEN & CO. LTD.
36 Essex Street, London W.C.i
First Published May rgth 1932
Reprinted zuiih minor corrections (Second Édition) July 1930
Reprinted 1954 and 1961
2.3
CATALOGUE NO. 2/5142/IO
Princed by photo-lithography at the Pitman Press, Bath
and bound by Jamas Burn & Co., London
PREFACE
T HIS book is the successor of a dissertation submitted
for the B.Sc. Degree in Oxford in 1922; but since
then it has been entirely re-cast, so that little if
anything of the original survives. I need hardly say that it
does not profess to cover the whole of the subject suggested by
the title. It is concerned in the main with only two points,
the nature of perceptual consciousness and the relation of
sense-data to the ordinary ‘ macroscopic objects' of daily life,
such as tables and rocks. On both those ponts what may be
called a causal theory has long been prevalent. It has been
held that sense-data are related to material things merely by
a rela.ti.on of indirect causal dependence (sometimes resemb­
lance has been added.) ; and that perceptual consciousness
either is, or at any rate ought to be, an argument from effects
to causes. This theory has of course been attacked, almost
from its beginning, by a long and illustrious series of philo­
sophers, from Berkeley to Mr. Bertrand Russell (in his middle
period) ; and its hold upon educated opinion has been further
weakened of late years by the spread of the ‘ descriptive ’
view of Science. But it is still so widely held, both by philo­
sophers and non-philosophers, and indeed has so many perfectly
legitimate attractions, that one more attempt to replace it by
something less violently opposed to Common Sense may not
be a waste of time. At any rate, I am convinced that the
theory is radically mistaken, and my main aim in this book,
whether worth achieving or not, is to present a constructive
and detailed alternative to it. If in so doing I seem to have
inclined too much to the opposite or Phenomenalistic extreme,
I can only plead that at least this is by far the lesser evil.
The main arrangement of the book is as follows. Chapter I
is cliiefly introductory, and seeks to establish the reality of
sensing and of sense-data. In chapter II, after stating the
main problem, which is arrived at by considering the various
meanings of the word ‘perceive’, I proceed at once to expound
vi PERCEPTION
and discuss a number of answers to it which. I hold to be erron­
eous : first Naïve Realism, both in its pure form, and in its
more subtle modern modifications (chapters II and III) ; and
then the Causal Theory (chapter IV) which I have stated as
sympathetically as I can, and in more detail than is customary,
in order to give it a fair run for its money. Chapter V is a
sort of interlude on the nature of sense-data, or as it is some­
times called, their ontological status. In chapters VI and VII
I have tried to give a description of our ordinary everyday
perceptual consciousness (this must be sharply distinguished
from the sensing by which it is accompanied and conditioned).
I have tried to show that it has its own criteria of validity,
and that no external ones are either necessary or possible.
In this connexion I wish to lay particular stress upon the fact
that perceptual consciousness has two distinct grades, which
I have called perceptual acceptance and perceptual assurance ;
the difference between them -has not, I think, been always
recognized. The subsequent chapters (VIII to X) are devoted
to the relation between sense-data and material things, which
following Professor G. E. Moore I have called the relation of
belonging to. This has involved me in a complex and I feax
somewhat tedious investigation of the relation of sense-data
to one another, the chief aim of which is to set clearly before
the reader's mind the notion of a family of sense-data.
Throughout this part of the book, as will be obvious to the
judicious student, I am very greatly indebted to the writings
of Professor G. E. Moore, Mr. Bertrand Russell, and Dr. C. D.
Broad ; but indeed their influence extends, in an only slightly
diminished degree, to the earlier chapters as well. In these
later chapters, and to some extent in the earlier ones also, I
have ventured to introduce a certain number of new technical
terms. This may distress some readers, but I think it should
assist most, for at least circumlocution is avoided and criticism
facilitated. I have done my best to state clearly what they
mean, and indeed in most cases their meaning is obvious.
Where they are inadequate perhaps they may stimulate some
one to produce better ones. In any case, nobody is obliged
to use them if he does not want to.
In conclusion I am bound to make grateful acknowledg­
ments to friends, teachers and colleagues, senior and junior,
both in Oxford and in Cambridge, to whom I owe both my
interest in this subject and my power to pursue it : in Oxford,
to Mr. H. W. B. Joseph, Professor H. A, Prichard and Professor
PREFACE vii
J. A. Smith, and among my own contemporaries to Mr. Gilbert
Ryle, Mr. J. D. Mabbott and Dr. A. C. Ewing ; and in Cam­
bridge to Professor G. E. Moore and Dr. C. D. Broad. I have
already mentioned my debt to the writings of Dr. Moore and
Dr. Broad, which are familiar to all English-speaking students
of Perception ; but thanks to their own kindness, and the
generous hospitality of Trinity College, Cambridge, I. have
also had the privilege of attending their lectures, and the still
greater privilege of private discussion with them. I wish I
could think that I had made due use of these advantages.
H. H. PRICE
Trinity College, Oxford
March, 1932
PREFACE TO 1954 REPRINT
This reprint of Perception is not a new edition. Apart from
a number of minor verbal changes and the correction of some
misprints, the book remains as it was when it first appeared
more than twenty years ago. A second edition would require
such drastic re-writing of the present text that the result would
be a new book, treating the subject on quite different lines.
If I were to undertake the task, I should try to state a theory of
perception much more ‘ Realistic’, much less close to Phenomen­
alism, than the one which is expounded here.
In the present book, the fundamental concept is that of a
sense-datum; and during the last twenty years, the sense-datum
analysis of perception has been very severely criticized by a
number of distinguished writers. With many of these criticisms
I agree, but not with all of them. I still think that the sense-
datum terminology is useful for purposes of phenomenological
description, where our aim is to describe how things look (sound,
feel, etc.) and not how they physically are. E03LESam.piaJ.llfi
world as a
scuse-data or something like it. Moreover, it is a strange
misunderstanding to assume, as some eminent thinkers have,
that visual sense-data must be ‘flat’, i.e. two-dimensional. It
is a plain phenomenological fact that visual fields have the
viii PERCEPTION
property of depth. And why should the sense-datum philo­
sophers, of all people, be supposed to deny this obvious fact?
On the contrary, they have usually been careful to emphasize
it; and in this book it is emphasized ad nauseam. Again, it has
sometimes been assumed that according to the sense-datum
philosophers, our ordinary perceptual experience consists of
nothing but the sensing of various sorts of sense-data. But
this is not what the sense-datum philosophers maintain. They
hold that the sensing is normally accompanied by something
else, called 'perceptual acceptance’ in this book—the belief
or the taking for granted that the sense-data we are aware of
belong..t,CLmaiemLohj£cr.s.
Nevertheless, I agree with the critics that the sense-datum
analysis is not the best starting-point for a discussion of normal
perception. A terminology devised for describing the way things
look, as distinct from the way they physically are, may lead
us to treat all perceptual experiences as if they were illusory
or hallucinatory ones; and thereby (like its predecessor, the
terminology of 'ideas’) it may lead us to doubt whether per­
ception can ever give us any knowledge of the material world
at all. We may come to feel that we are irremediably cut off
from the material world bv an ‘iron curtain' of sense-data.
But there seems to be something logically incoherent about
such scepticism. To make someone understand the sense-datum
terminology, we have to give him suitable instructions. ‘Look
at a pencil. Push one of your eyes aside with your finger. There
will now be two elongated colour-expanses in your visual field,
whereas there was only one before. These two colour-expanses
are visual sense-data.’ The words I have italicized are material
object words, belonging to the everyday material-object vocabu­
lary of common sense. The same might be said of the command
‘look at’, with which the instructions began. It is naturally
taken to mean 'direct your eyes towards’. If these instructions,
and others like them, are to be understood, the material-object
language of common sense must be understood already. And
how can we have learned to understand it, unless some material-
object words have ostensive definitions? To say the same
thing otherwise, it-would seem tha,L.a.t least. some material-__
object concepts must be empirically cashable bv a direct
awareness of the objects which are instances of them. In that
case, there must surely be something wrong with the sceptical
doubts into which the sense-datum terminology (when once
we have learned to use it) is liable to lead us. If the doubts
PREFACE ix
had been well-founded, the terminology itself could, never have
been understood.
I am inclined to agree with another point on which the
critics of sense-d.ata have insisted. They contend that in ordi-.
narv perceptual experience we are never aware of sense-data
a,t all; that an ordinary perceptual experience is just an
awareness of material objects and physical happenings, such
as clouds, trees, and thunderclaps. On this view, what the
sense-datum philosophers call 'sensing’ and take to be a
constituent of all perceptual experience, should rather be called
phenomenological inspection. The attitude of phenomenological
inspection, it would be said, is only attainable by a very con­
siderable voluntary effort, and is something quite outside the
experience of the ordinary percipient. But unless we can
manage to get ourselves into this special attitude (and. even
some philosophers, it would seem, are incapable of doing so)
we shall not be able to notice the facts which the sense-datum
theorists are trying to describe. It does not, of course, follow
from this that the facts are not there to be noticed, nor that
they are unimportant, nor that a terminology designed to
describe them is useless. But it does follow that a terminology,
or a conceptual apparatus, which is suited for this special
purpose is not the appropriate one to use when our aim is to
analyse ordinary perceptual experience.
Nevertheless, despite the force of these criticisms, I hope
that the book may still have some value as it stands. It may
serve at least as a useful Aunt Sally, and beginners may exercise
their minds by detecting its inadequacies. It may have a
certain historical interest, as a typical product of a now remote
philosophical epoch. Its whole approach to the problems of
perception may be misguided, or over-narrow, or just mistaken.
But the reader may still learn something by seeing what this
approach leads to, when an attempt is made to work out its
implications in detail. The central concept of this book, the
concept of a sense-datum, may be regarded as an analytical
tool. The value of such a tool cannot be judged by a priori
arguments. The only way to judge it is to see what clarificatory
(or obfuscatory) power it shows when it is actually applied.
H. H. PRICE
CONTENTS
CHAP. PAGE
Preface . . . . . . . . . v
I The Gi v e n .......................................................................................i
II Naïve Realism and the Argument prom Illusion . 21
III Some Modifications of NaTve Realism 55
IV The Causal Theory............................................................... 6 6
V The Nature of Sense-Data . . . . . 103
VI Perceptual Consciousness. I. Perceptual Accept­
ance . .......................................................................... 139
VII Perceptual Consciousness. II. Perceptual Assur­
ance ....................................................................................................170
VIII The Relation of Sense-Data to One Another . 204
IX The- Relation of Sense-Data to Matter . . 273
X The Origination of Sense-Data . . . . 309
Index . . . . . . . . . 323
xi
P E R C E P T I O N
CHAPTER I
THE GIVEN
EVERY man entertains a great number of beliefs concern­
ing material things, e.g. that there is a square-topped
table in this room, that the earth is a spheroid, that
water is composed of hydrogen and oxygen. It is plain that
all these beliefs are based on sight and on touch (from which
organic sensation cannot be separated): based upon them in
the.sen^thatii,j^Aad.aot.hMxextam.piartfc^r.exp£xiences
<?f seeing and touching, it would be neither possible nor reason­
able to entertain these beliefs» Beliefs about imperceptibles
such as molecules or electrons or X-rays are no exception to
this. Only they are based not directly on sight and touch, but
indirectly. Their directjjasis consists of certain other beliefs
concerning scientific instruments, photographic plates, and the
like. Thus over and above any intrinsic uncertainty that they
themselves may have, whatever uncertainty attaches to these
more basic beliefs is communicated to them. It follows that
in any attempt either to analyse or to justify our beliefs con­
cerning material things, the primary task is to consider beliefs
concerning perceptible or ‘ macroscopic ' objects such as chairs
and tables, cats and rocks. It follows, too, that no theory
concerning' microscopic ’ objects can possibly be used to throw
doubt upon our beliefs concerning chairs or cats or rocks, so
long as these are based directly on sight and touch. Empirical
Science can never be more trustworthy than perception, upon
which it is based ; and it can hardly fail to be less go. since
among its non-perceptual premises there, can hardly fail to be
SQme which are neither self-evident nor demonstrable. Thus
the not uncommon view that the world which we perceive is an
illusion and only the ' scientific ’ world of protons and electrons
is real, is based upon a gross fallacy, and would destroy the
very premises upon which Science itself depends.
i
2 PERCEPTION
My aim in this book is to examine those experiences in the
way of seeing and touching upon which our beliefs concerning
material things are based, and to inquire in what way and to
what extent they justify these beliefs. Other modes of sense-
experi'ence, e.g. hearing and smelling, will be dealt with only
incidentally. For it is plain that they are only auxiliary. Jf
we possessed them, but did not possess either sight or touch,
we should have no beliefs about the material world aialJk
should lack even the very conception of it. Possessing sight
or touch or both, we can use experiences of these other senses
as signs of obtainable but not at the moment actual experiences
of seeing or touching, and thereby gain indirectly information
which these inferior senses in themselves provide no hint of.
It may appear to some people that. Science, particularly
Physiology, can answer these questions for us. But it should
already be clear that this is a mistake. Thus if it be said that
when a man sees something, e.g. a tomato, light rays emanating
from the object impinge upon his retina and this stimulates the
optic nerve, which in turn causes a change in the optic centres
in his brain, which causes a change in his mind: there are two
comments to be made. i. No doubt this is in fact a perfectly
true account, but what are our grounds for believing it ?
Obviously they are derived from observation, and mainly if
not entirely from visual observation. Thus the Physiologist
has not explained in the least how visual observation justifies a
man in holding a certain belief about a tomato, e.g. that it is'
spherical. All he has done is to put forward certain other
beliefs concerning a retina and a brain. Those other beliefs
have themselves to be justified in exactly the same way as the
first belief, and we are as far as ever from knowing what way
that is. Instead of answering our question, we have found
another instance of it. Nor is this result surprising. Since
the premises of Physiology are among the propositions into
whose validity we are inquiring, it is hardly likely that its
conclusions will assist us. 2. In any case, Science only pro­
fesses to tell us what are the causes of seeing and touching.
But we want to know what seeing and touching themselves are.
This question lies outside the sphere of Science altogether.
Thus there is no short cut to our goal. We must simply
examine seeing and touching for ourselves and do the best we
can. What, then, is it to see or to touch something ? Let us
confine ourselves to sight for the moment and return to the
instance of the tomato.