The Competitiveness of Nations in a Global Knowledge-Based Economy
Michael
Polanyi
Tacit Knowing: Its Bearing on Some Problems of Philosophy
Reviews of Modern Physics, 34 (4)
Oct. 1962, 601-616.
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Content
Part III: Primary & Secondary Qualities
HHC: titles
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IN this paper I shall try to carry further, in
outline, an inquiry that I have been pursuing for several years. For this purpose, it is necessary, first of
all, to recapitulate some arguments which I have developed elsewhere.
There are things that we know but cannot tell. This is strikingly true for our knowledge
of skills. I can say that I know
how to ride a bicycle or how to swim, but this does not mean that I can tell
how I manage to keep my balance on a bicycle or keep afloat when swimming. I may not have the slightest idea of how I do
this, or even an entirely wrong or grossly imperfect idea of it, and yet go on
cycling or swimming merrily. Yet, it
cannot be said that I know how to bicycle or swim and not know how to
coordinate the complex pattern of muscular acts by which I do my cycling or
swimming. It follows that I know how to
carry out these performances as a whole and that I also know how to carry out
the elementary acts which constitute them, but that, though I know these acts,
I cannot tell what they are.
We perform a skill by relying on the coordination of
elementary muscular acts, and we are aware of having got these
right by accomplishing our skillful performance. We are aware of them in terms of this
performance and not (or only very incompletely) aware of them
in
themselves.
This fact can be generalized widely. There are vast domains of knowledge, of which
I shall speak in a moment, that exemplify, in various ways, that we are
generally unable to tell what particulars we are aware of when attending to a
coherent entity which they constitute. Thus,
there are two kinds of knowing which invariably enter jointly into any act of
knowing a comprehensive entity. There is
(1) knowing a thing by attending to it, in the way we attend to an
entity as a whole and (2) knowing a thing by relying on our awareness of it
for the purpose of attending to an entity to which it contributes. The latter knowledge can be said to be tacit,
so far as we cannot tell what the particulars are, on the awareness of which
we rely for attending to the entity comprising them.
These two kinds of knowing are not only distinct, but
also in an important sense mutually exclusive. Motion studies may teach us to identify some
of the elementary acts constituting a skill, and this may be useful in
training. But, while attending to the
elements of a skill in themselves, we impair their smooth integration to the
joint performance that it is their function to serve. If we succeeded in focusing our attention completely
on the elements of a skill, its performance would be paralyzed altogether.
The mutual exclusiveness of the two kinds of knowing
can be expressed in terms of a logical disjunction. When we know something by relying on our
awareness of it for the purpose of attending to something else (i.e., we know a
particular for the purpose of attending to a comprehensive entity to which it
contributes), we cannot at the same time not rely on it for this purpose
- as would necessarily be the case if we attended to it exclusively in itself.
We may call “knowing by attending to” a focal knowing,
and “knowing by relying on” a subsidiary knowing, and reformulate in
these terms the conclusions we have arrived at as follows. We know subsidiarily
the particulars of a comprehensive whole when attending focally to the whole
which they constitute; we know such particulars not in themselves but in terms
of their contribution to the whole. To
the extent to which things are known subsidiarily in
terms of something else, they cannot be known at the same time in themselves.
We may call the bearing which a particular has on the
comprehensive entity to which it contributes its meaning, and can then
say that when we focus our attention wholly on a particular, we destroy its
meaning. My introductory statement,
that there are things that we know but cannot tell, can then be developed as
follows. We can tell what the things are
which we know by attending to them focally, but we are uncertain, or entirely
ignorant, of things that we know only by relying on our awareness of them for
attending to something else, which is their meaning.
601
What is subsidiarily known
is tacitly known; but it seems appropriate to extend the meaning of “tacit
knowing” to include the integration of subsidiary to focal knowing. The structure of tacit knowing is then the
structure of this integrative process, and knowing is
tacit to the extent to which it has such a structure. So if (as it will appear) all knowing
ultimately relies on a tacit process of knowing, we shall say that, ultimately,
all knowledge has the structure of tacit knowledge.
Tacit knowing cannot be strictly opposed to focal
knowing because the process of tacit knowing includes our knowing of the
subsidiary particulars in terms of the entity to which they contribute and to
which we are focally attending. But the
tacit character of knowing can be reduced by switching our attention to
the particulars. We replace then, to
this extent, tacit knowing by explicit inference, and in
this sense tacit knowing can be opposed to (focally known)
explicit
inferences.
Four points must yet be clarified.
(1) I have mentioned that motion studies can identify
some of the muscular acts which contribute to a skill. Let us be clear that this does not contradict
my statement that we can know things we cannot tell, for previous to the
motion study we knew how to perform and coordinate these muscular acts, but
could not tell what they were. It may be
possible to find out how we keep our balance on a bicycle or keep afloat when
swimming, but we can know how to cycle and swim without having found out
how we do it. Besides, motion studies
are always incomplete, as can be seen from the fact that you cannot acquire a
skill merely by learning to perform its fragments, but must also discover the
knack of coordinating them effectively. I shall clarify this further in my next point.
(2) It may be said that since we can teach a skill, we
can, in fact, also convey the knowledge of how to perform the several muscular
acts of such a skill. The answer is that
to the extent to which our teaching will have to rely for its success on our
pupil’s intelligent and dexterous effort to carry out our instructions, we are,
in fact, not defining what he has to do. Definitions of terms bearing on external objects
must always ultimately rely on pointing at things that are instances of what we
mean. This is called an “ostensive
definition”; but this term conceals a gap to be bridged by an intelligent
effort of the person using our definition. If he succeeds in bridging this gap, he will
have discovered for himself something we have not been able to tell him. This is the sense in which I say that we
can know things we cannot tell.
(3) Is subsidiary knowledge the same as unconscious
knowledge? No, the two must not be
identified. Subsidiary and focal
awareness are different in kind. Focal
awareness is always conscious, whereas subsidiary awareness may range from a
conscious level, down to levels altogether inaccessible to consciousness. A skier racing down a slope is intensely aware
of controlling every part of his body, though he could not tell by what
principles he keeps his balance. By
contrast, studies by Hefferline and his collaborators
have shown that a human subject can learn to silence an unpleasant noise by a
muscular twitch so slight that he cannot feel it at all. [1] When tacit knowing relies
on such low levels of consciousness, it becomes unspecifiable
in a stronger sense.
(4) The experiment I have just quoted is an outstanding
example of an inquiry in which an increasing number of experimental
psychologists have been engaged in the past ten years and that has aroused wide
popular interest - the inquiry into the process now usually called ‘subception.’ The
term was coined by Lazarus and McLeary. [2] A number of nonsense
syllables were briefly shown to the subject and certain of these were followed
by an electric shock. Presently the
subject anticipated shock on the sight of “shock syllables,” but, on
questioning, he wrongly identified these syllables; this was called ‘subception.’
The authors acknowledge similar experiments by earlier
authors and they were followed by a number of others demonstrating variants of subception in the anticipation of shock. [3] In all these cases the
subjects had acquired knowledge, the particulars of which they could not
specify. However, once these particulars
were identified, they could be readily observed in themselves. Some subjects of Ericson
and Kuethe did in fact consciously avoid shocks, and,
in consequence, behaved differently from those avoiding shocks by subeeption. By
contrast, Heiferline’s experiments represent a subception of subliminal stimuli. Earlier observations of this type are
exemplified by the work of Smith and Henrickson. [4] They exposed the picture
of a smiling face so briefly, that it could not be identified, and found that
unsmiling faces exposed immediately afterwards (long enough to be identified)
were seen as smiling slightly.
1. See Hefferline, Keenan, and Harford,
Science 130, 1338 (1959). (The twitches
were observed by registering their action currents, amplified one million
fold.)
2. Lazarus and McLeary, J. Person.
18, 171 (1949); Psychol. Rev.
58, 113 (1951).
3. Cf. Lacey and Smith [Science 120, 1045 (1954)] who refer back
to K. Diven [J. Psychol.
3, 291 (1937)] and J. G. Miller [Feelings and Awareness (New York
1950)]; also Ericson and Kuethe
[J. Abn.
Soc. Psychol. 53, 203 (1956)];
and Razran [Psychol.
Rev. 68, 81 (1961)].
4.
Smith and Henrickson, Acta Psychol. 11, 346 (1955)
Summing up the whole position, as Sectional President
of the British Association for the Advancement of Science at its meeting of
1959, Vernon [5] acknowledged a “... type of perception of which we are not
directly aware, but which nevertheless affects our actions in some ways.”
These observations of subception
strikingly confirm the relation between the subsidiary and focal awareness, as
a relation between “awareness by relying on” for the purpose of an “awareness
by attending to” - a relation that I had derived from the findings of Gestalt
psychology. It would seem, therefore,
that observations of subception are but an
experimental demonstration of the integration of particulars to form a gestalt
- the particulars being sometimes subliminal.
This view of the situation finds support in an
analysis by Klein. [6] He
notes that learning to avoid items inducing electric shock, without being able
to tell which these items are, is but a variant of the way we recognise a physiognomy without being able to tell what
features we distinguish it by. [7] Klein also offers
evidence that subliminal activation is but a special instance of transient or
incidental stimuli of all kinds. In his
view it is not so much the subliminal status that is characteristic of such a
stimulus than “the meanings and properties it acquires ... at the periphery of
thought and action.”
This is consonant with my conclusion that subsidiary
awareness may range from a conscious level, down to levels altogether
inaccessible to consciousness. I consider,
therefore, that the evidence found for subception is
an experimental illustration of the relation between a subsidiary and a focal
awareness. And that, accordingly,
wherever
I shall speak of the unspecifiable particulars that
are known to us in terms of a comprehensive entity to which they contribute, I
may be taken to speak of a form of subception.
We now pass on to other forms of tacit knowing, the
structure of which is similar to that of knowing a skill. We can find most of these taught in the laboratories
and hospitals of universities. Among the
main things taught there is how to identify specimens by their characteristic
appearance.
Textbooks of diagnostics teach the medical student the
several symptoms of different diseases, but this knowledge is useless, unless
the student has learnt to apply it at the bedside. The identification of the species to which an
animal or plant belongs, resembles the task of diagnosing a disease; it too can
be learnt only by practicing it under a teacher’s guidance. A medical practicioner’s
diagnostic ability continues to develop by further practical experience; and a
taxonomist can become an expert, e.g., for classing new specimens of insects
(of which 800,000 are known), only after many years of professional practice. Thus, both the medical diagnostician and the
taxonomist acquire much diagnostic knowledge that they could not learn from
books.
The art of recognizing a characteristic appearance by unspecifiable particulars is actually quite common. We practice it every day when watching the
delicately varied expressions of the human face, and recognizing its moods
without being able to identify, except quite vaguely, the signs by which we do
so. This is also the way in which we
commonly recognize a familiar face. Any
description we can give of a person will usually apply equally to millions of
other people, from all of whom we could distinguish him at a glance. The number of elements involved in such
discrimination can be illustrated by the way in which the British police
construct the likeness of a person whom a witness has seen. They use a slide file of 550 facial
characteristics, such as different sets of eyes, lips and chins. The witness picks the individual features that
most closely resemble his idea of the criminal’s face, and from this selection
a composite picture is assembled. Even
so, such a picture can merely serve as one clue among others. For the identification of a person is such a
delicate operation, that even a genuine photograph of him may not suffice. When Claus Fuchs was shown pictures of a man
called Gold who was suspected of being his accomplice, he hesitated to identify
him, and only when a film was shown of Gold walking
about, did Fuchs recognize him. A witness
may fail to recognize a person by a photograph, but pick him out at an identification
parade.
We have seen that recent studies of subception have confirmed experimentally the fact that we
can know how to discriminate a complex pattern of things, without being able to
tell by what features we discriminate it. Though studies of subception
have covered only a narrow section of unspecifiability
and have thrown no light on its structure, they may convince even the most
reluctant minds of the existence of unspecifiable
knowledge.
The characteristic appearances of a disease; of the specimen of a
species; of the mood in a face; of the identity of a person, I shall call their
physiognomy. The structure of
tacit knowing which recognizes a physiognomy resembles that of a skill. It is an intel-
5. M. D. Vernon, Advancement of Science
16, 111 (1959).
6. George S. Klein, J. Nerv. Dis. 128, 293 (1959).
7. “It requires no
experimental demonstration to say confidently that we are not aware of all the
stimuli which we use in behavior,” G. S. Klein, reference 6.
603
lectual skill, in
which a complex pattern of delicately graded features takes the place of a dexterously
coordinated set of muscular acts. We do
not attend to these features and their pattern in themselves,
but rely on our awareness of them for attending to the physiognomy to which
they jointly contribute. Hence, we know
a physiognomy but cannot tell, or only inadequately tell, how we recognize it.
We know the unspecifiable
particulars of a physiognomy only in terms of its total appearance. They serve us as clues, which we have
learned to integrate by a practiced effort of intelligence. Thus we achieve the understanding of a
physiognomy, which is the intellectual counterpart of the performance of
a skill.
Although the analysis of a physiognomy tends to make
us lose sight of it as a whole, it will deepen our understanding of it if
followed by a renewed integration of its separated elements; this is analogous
to the effect of motion studies. Some of
the clues to a physiognomy may be so slight as not to
be noticeable in isolation, others are experienced on the same level of
consciousness as the physiognomy to which they contribute. But when any particular clue of a physiognomy
is isolated and thereby ceases to function as a clue, it looks different from
what it looked like as a clue. Gestalt
psychology, on which I am drawing throughout this attempt to establish the
logic of tacit knowing, has given many examples of
this fact.
The characteristic physiognomy of a man may be said to
be the meaning of the clues which point to it; but a physiognomy is itself a
clue to something else, namely, to the mood that it expresses, or, more
generally, to the mind at work in it. The same principle applies to all other cases
of skilful diagnosing. The comprehensive
entity that we identify in meeting an acquaintance is not his appearance, but
his person; the medical practicioner does not
diagnose the appearance of a disease, but its presence; and the same is true
when we identify a specimen of a species. We may say, also, that our performance of a
skill presents a permanent coherent entity forming part of our bodily equipment,
though such a practical entity is, admittedly, less substantial than the things
comprehended by identifying a physiognomy.
Owing to the structural kinship of the two leading
types of tacit knowing (the practical and the intellectual), these two are
always found combined to some extent, and are sometimes found combined equally.
This is true for the art of testing which
is widely taught in practical classes and teaching hospitals. Medical percussion is a delicate skill combined
with a joint appreciation of tactile and audible clues elicited by the
percussion, and such a test is itself to be interpreted within a comprehensive
set of other tests, all of which combine the exercise of practical and
intellectual skills. We shall presently
meet other intimate combinations of these two kinds of skills in the process of
visual perception.
Meanwhile, I shall pass from the performance of tests
to use of tools in general. Tools
are akin to the particulars of a comprehensive entity, for an object is a tool
by virtue of the fact that we rely on it for accomplishing something to which
we are attending when using the tool. In
this case we can, admittedly, identify the thing on which we rely, even though
mostly we do not quite know how we actually use it. But it is still true that we cannot direct our
attention to a tool as a mere object, while relying on it as the tool of a
skilful performance. You must keep your
eye on the ball, and if you look at your bat instead, you lose the stroke. A skilful performance is paralyzed by
attending focally to its particulars, whether these are the dexterous movements
of our body or the tools which we employ.
The skilful use of a tool actually identifies it to an
important extent with our own body. The
rower pulling an oar feels its blade tearing the water; when using a
paper-knife we feel its edge cutting the pages. The actual impact of the tool on our palm and
fingers is unspecifiable in the same sense in which
the muscular acts composing a skilful performance are unspecifiable;
we are aware of them in terms of the action our tool performs on its object,
that is, within the comprehensive entity into which we integrate the effective
use of a tool. The same is true of a
probe used for exploring a cavity or a stick by which a blind man feels his
way. The impact made by a probe or a
stick on our fingers is felt at the tip of the probe or stick, where it hits an
object outside, and in this sense the probe or stick is integrated to our
fingers that grasp it.
A feature of great importance enters here in the way the assimilation
of an instrument to our body is achieved gradually by learning to use the
instrument intelligently. When first
groping our way blindfold with a stick, we feel it jerking against our hand. But as we learn to understand these jerks in
terms of the impacts of the stick against outer objects, we begin to feel the
end of the stick knocking at these objects. Thus the jerks against our hand, when
integrated to our purpose, undergo (along with a change in quality) a
transposition in space. We see here
that when a particular is integrated into a comprehensive entity it may acquire
a meaning which is sensed at some distance from the original
position of the particular, at which it had
been previously experienced in itself, meaninglessly. Other examples of such shifts, directed likewise
away from our body, will be met in the use of language and the act of visual
perception.
We can pass from probes to language by thinking
of pointers. We rely on our awareness of
a pointer in order to attend on what it points at, and this is its meaning. Seen in itself, as a mere object, the pointer
is meaningless. Words used in speech
and, more particularly, nouns, verbs, and adjectives, are used like pointers to
designate things they mean. The
comprehensive entity to which we are attending in meaningfully uttering such
words is, to use E. C. Tolman’s term, a sign-gestalt:
It is our act of designating something and the means for doing so, when jointly
experienced as pointing to that which we designate. Owing to the partial transposition of this
experience to a distance, by which it is attached to the designated object,
this object becomes in effect what we mean by our utterance.
When we identify the elements of speech to which we
are not attending at the time of our utterance, and switch our attention to
them, our utterance becomes meaningless. Repeat the word table, table, table, twenty
times over, attending carefully to the sound of the movement of your lips and
tongue, and the meaning of the word will become remote, and finally dissolve
altogether. That is often expressed by
saying that words used meaningfully are transparent and that, when we
concentrate on a word as a sound, it becomes opaque. The transparent word is like a telescope
through which we see its meaning - while, when rendered opaque, the word ceases
to show us things beyond itself and blocks our sight
by its own meaningless body. To make
explicit our tacit knowledge of a spoken word is to destroy the comprehensive
entity, the sign-gestalt, to which the word contributed.
This example of tacit knowing has extended the scope
of the term. A tacit coefficient now
appears to be integral to all explicit statements. The bearing of a statement on experience can
only be known tacitly; no statement can carry conviction unless it is understood,
and all understanding is tacit.
Tacit knowing can, indeed, be identified with
understanding, if understanding is taken to include the kind of practical
comprehension which is achieved in the successful performance of a skill. This being allowed for, understanding may be
recognized as the faculty, cast aside by a positivistic theory of knowledge,
which the theory of tacit knowing acknowledges as the central act of
knowing. In this sense the practice
of skills, the diagnosing of physiognomies, the performance of tests, the use
of tools and probes, and the meaningful uttering of denotative words, are so
many acts of understanding complex entities.
Finally, among the most primitive forms of knowing, we
meet the act of visual perception, and find in it the very paradigm of
that structure of comprehension that I have postulated for knowledge at all
levels. Seeing has supplied Gestalt
psychologists with material for their discoveries which I am expanding here into
a theory of knowledge. They have shown
that our seeing is an act of comprehension for which we rely, in a most subtle
manner, on clues from all over the field of vision, as well as on clues inside
our body, e.g., in the muscles controlling the motion of the eyes and in those
controlling the posture of the body. All
these clues become effective only if we keep concentrating our attention on the
objects we are perceiving. Many of the clues of perception cannot be
known in themselves at all; others can be traced only by acute experimental
analysis; but all of them can serve the purpose of seeing, only if we make no
attempt at attending to them in themselves. They must be left to abide in the role of
particulars of which we are aware in terms of the spectacle perceived by our
eyes, if we are to see anything at all. The
clues on which we rely for looking at an object will then appear to us in terms
of the shape, color, size, position, and other visible features of the object. This is their meaning to us; and this meaning
is considerably displaced away from our body, where many of its clues are
situated.
To introduce the bearing of my analysis of tacit
knowing on some problems of philosophy, I shall deal with a question raised
fairly recently by Brain. Having noted
the curious fact that some patients feel part of their body to be an external
object, the author raises the question as to how we normally distinguish our
body from external objects. [8] He
suggests that ‘dropableness’ is the quality by which
a small object differs from a part of one’s own body.
But we do distinguish our own body also from objects, whether small or large, that are not dropable. The distinction lies deeper. The unique character of our body lies in the fact that it is the only collection of things which we know almost exclusively by relying on our awareness of them for attending to some-
8. W. Russel Brain, Mind, Perception and Science (Oxford University
Press, New York, 1951), p. 18. “…‘dropableness’ is
the primary quality which distinguishes a small body from a part of one’s
body.” The author says nothing about
large bodies.
605
thing else. All parts of our body serve us as tools for
observing objects outside us and for manipulating these for purposes of our
own. Every time we make sense of the
world, we rely on our tacit knowledge of impacts that the world makes on our
body and of the responses of our body to these impacts. Hence, the exceptional position of our body in
the universe.
But hence also our capacity for
assimilating to ourselves things outside, by relying on our awareness of them
for attending to something else. When
we use a tool or a probe and, above all, when we use language in speech,
reading, or writing, we extend our bodily equipment and become more effective
and more intelligent beings. All human
thought comes into existence by grasping the meaning and mastering the use of
language. Little of our mind lives in
our natural body; a truly human intellect dwells in us only when our lips shape
words and our eyes read print.
Tacit knowing now appears as an act of indwelling by
which we gain access to a new meaning. When
exercising a skill we literally dwell in the innumerable muscular acts which contribute
to its purpose, a purpose which constitutes their joint meaning. Therefore, since all understanding is tacit
knowing, all understanding is achieved by indwelling. The idea developed by Dilthey [9] and Lipps, [10] that we can know human beings and works of
art only by indwelling, can thus be justified. But we see now also that these authors were
mistaken in distinguishing indwelling from observation as practiced in the
natural sciences. The difference is only
a matter of degree: Indwelling is less deep when observing a star than when
understanding men or works of art. The
theory of tacit knowing establishes a continuous transition from the natural
sciences to the study of the humanities. It bridges the gap between the I-It and the I-Thou, by rooting them both in the subject’s I-Me
awareness of his own body, which represents the highest degree of indwelling.
We can extend this perspective to include a more
ancient philosophical problem. Galileo,
Locke, and their successors, have taught that external objects are merely
masses in motion and that the sights, sounds, and smells which appear to belong
to them, are not actually theirs but are generated in us by the impact of
motions coming from them into our eyes, ears, and noses. Modern neurology has borne out the belief in
the internal location of colors, sounds, and smells, by proving that they can
be produced internally as afterimages, illusions, or hallucinations. Furthermore, it has gone beyond this by
tracing the neural processes by which the external impact is conducted to the cerebral
cortex and identifying the several cortical centers which produce our awareness
of sights, sounds, and smells. Modern
knowledge has thus added compulsive force to the philosophical problem: How do
we come to know external objects, if our awareness of them is altogether
internal?
The current remedy of analytic philosophy is to
restrict the applicability of terms like ‘seeing,’ ‘hearing,’ ‘smelling’ to
what is experienced by the speaker, disregarding the neural and cortical
processes which underlie these experiences. This usage, however, is not acceptable, for it
would ban the language of sense physiology and thus ignore all its discoveries.
An earlier school of thought, originating with Lord
Russell, assumes that the sights, sounds, etc., arise inside the brain where
room is made for them by postulating a private perceptual space, as distinct
from the physical space in which the brain itself is located. Lord Brain developed this idea further by
assuming that these sensory qualities are experienced in the brain not in
themselves, but as symbols by which we become aware of external objects with
their corresponding qualities of color, sound, smell, etc. Sensory experiences are compared to the
pictures on a radar screen on which we can observe distant objects. But since the question is left open as to who
interprets the symbols and by what means, or who watches the radar screen and
how he interprets its signs, Lord Brain’s explanation brings us back to the original
question, how we come to know external objects, of which we are originally
aware internally.
Let us look at this question within the framework of tacit knowing. Remember the way we know skills and physiognomies, make tests, use tools and probes, utter
words, and the way I have fitted visual perception into the structure that
applied to all other instances of tacit knowing. These were all shown to be particular
instances of the fundamental fact that we are able to make sense of clues or
particulars to which we are not attending at the moment, by relying on our
awareness of them for attending to something else - so that the appearance of
that to which we are attending, may be said to be the meaning of these clues or
particulars. Once we had grasped this
way of making sense, we also realized that the position at which the meaning of
the clues appeared to be situated did not coincide with the position of the
clues themselves and could lie in some cases nearer to, in others further away
from them. We have seen that in.
9. Cf., e.g., W. Dilthey Gesammelte Schriftem (Leipzig and Berlin, 1914-36), Vol. VII, p.
213-216; [translation by H. A. Hodges, Wilhelm Dilthey
(Oxford University Press, New York, 1944, p. 121-124].
10. T. Lipps,
Asthetik (Hamburg, 1903).
the use of tools and probes the impact that their handle makes on our
hands and fingers is not felt in itself at the place where it happens, but as
an impact of our instrument where it hits its object. A similar process of integration rendered
spoken words transparent, their meaning being found in the things they
designate. Visual perception appears
then as yet another instance of relying on a wide variety of clues, some
inside, some outside our body, for attending to their joint meaning, which in
this case appears to us in terms of the shape, color, size, position, and other
visible features of an object.
Many of these clues, particularly those inside our
body, cannot be experienced in themselves by those who use them. Their existence is revealed only by the
physiological observation of the bodily processes affecting the way a subject
sees things. But this does not
distinguish visual perception from other instances of tacit knowing. I have quoted an experiment showing that we
can actually be trained to control external events by minute muscular contractions
which are too weak to be felt in themselves. All the physiology of vision can thus be
assimilated to previous instances of tacit knowing. The fact that the physiologist may be capable
of tracing all the relevent clues of an act of visual
perception without being able to rely on these clues for seeing what they mean
to the subject, in the same way as he sees it, might be regarded as an instance
of the destruction of meaning which takes place when we focus our attention on
the isolated particulars bearing on a comprehensive entity. We may look upon this also as the difference
between degrees of indwelling. The
subject’s awareness of his own neural processes has a much higher grade of
indwelling than the physiological observation of them. [11]
One may distinguish, of course, between our awareness
of subliminal impacts on, or in, our body and neural processes at cortical
centers to which all stimuli are conducted; but this difference does not affect
the issue. For we know that sensations
which are primarily felt at some point of our body may come to be felt further
out in space, for example at the tip of a probe, and that we can be conditioned
to respond to impacts inside our body that are too weak to be felt at that
point at all. Hence, if we were to assume
that sensory experiences do occur in the first place in the cortex, we might
still expect that a process of tacit knowing would make us sense them
elsewhere; so that our assumption that they had occurred originally in a place
where we do not feel them, would not present any new problem.
This view of the localization of sights seen does not
tell us how such sights, or any other states of consciousness, arise from (or
in conjunction with) neural processes. This
problem is set aside in this paper. We
only assume that whenever we have conscious experiences, we also have
the power of integrating them meaningfully. It is by this power then that we see things as
we do, and the fact that the physiologist does not see these things when
observing the visual processes in the cortex, can be ascribed to the fact that
he attends to these neural processes in themselves. The rest of this paper will serve mainly to
consolidate and elaborate this conclusion.
It is interesting to compare, with this in mind, the process of
integration by which we arrive at tacit knowing, with a formal process of
inference by which we might arrive at the same conclusion. Optical illusions offer a good example for
such an enquiry. In a famous experiment
of Ames we are facing the wall of a room in which we see one corner occupied by
a. small boy and the opposite corner by a grown man. An illusion makes us see the boy as taller than
the man. This is due to the skew shape
of the room, which we had not noticed. In
this room, the distance between ceiling and floor is much less at the other
corner where the man is placed. At the
same time the boy’s corner is nearer to us than the man’s. Helmholtz (1866) has
described perception, including optical illusions, as the result of unconscious
reasoning. In this case the premise of
such reasoning would be, that rooms are right-angled parallelepipeds in which
(1) the distance between ceiling and floor is everywhere the same and (2) from
a point facing the-middle of a wall the two corners of the wall are equidistant.
Hence a boy whose head touches the
ceiling is taller than a man whose head leaves a gap of a foot or so under the
ceiling; the more so, if the angle of vision enclosing the boy, from head to
foot, is correspondingly larger than the angle under which the man is seen. To be more precise, we would have to introduce
an intermediate state of reasoning which causes us to see the skew shaped room
as if it were normal. The experiment is
arranged in such a manner that from the point from which we view the room, the
angles of vision by which we see its corners are the same as they would be for
a normal room. This fact is taken to
confirm with respect to the room in
11. This is not to accept the distinction of two kinds of experience,
one from inside, the other from outside.
The physiologist’s view of organs and their functions is an internal
comprehension of a living being, compared with a purely physical and chemical
topography of a living body which would contain no such understanding. I am envisaging a continuous range in degrees
of indwelling; not two aspects, one from inside, the other from outside.
607
front of us, our major premise, that all rooms
are right-angled parallelepipeds.
In terms of tacit knowing we would say that we rely on
our awareness of numberless rooms seen before, and of the other elements of the
framework within which the two figures are presented to us, and integrate all
these particulars into the way we see the boy and the man on whom our attention
is focused.
Optical illusions cannot, as a rule, be dispelled by
recognizing them to be illusory, and psychologists have refused to follow Helmholtz in describing as unconscious reasoning a process
which compels our assent to what we know to be false. The question is whether we can substantially
recast this discussion by classing an optical illusion as a case of mistaken
tacit knowing.
I think we can, for the analysis of an optical
illusion in terms of an unconscious inference corresponds to a process that
fulfills an important function in respect of all manner of tacit knowing. It belongs to the same class as (1) the
analysis of skills by motion studies, (2) the characterization of a physiognomy
by listing its typical features, (3) the giving of detailed directions for
carrying out a test or using a tool, (4) the analysis of speech by grammar, and
(5) the physiological analysis of perception.
This may appear a bewilderingly disparate collection,
remote from the interpretation of optical illusions as a process of unconscious
reasoning. And this impression is
hardened if we realize how vast are some of the areas I have
set out here. Motion studies
should be taken to include the practical teaching of every kind of artistic
performance, of all skilled workmanship, and all manner of sports. The analysis of physiognomies covers an even
richer field. It includes, along with
the diagnostics of medicine and taxonomy, all criticism of art and literature,
by which our understanding of paintings, architecture, music, poetry, drama,
and fiction is educated, guided, and deepened. The analysis of speech includes, in addition
to grammar, the study of voice production and phonetics, as well as
lexicography, stylistics, and rhetoric. The
field extends further to analytical philosophy, which studies language rules,
with a view to the clarification of philosophic problems. Finally, the theory of perception, which
stands last on my list, is but an example of the whole range of sense
physiology with its roots spread over anatomy, neurology, and psychology, with
the selection of its particular subjects taken from the entire range of the
animal kingdom.
Yet all these inquiries have it in common with each
other and with the analysis of optical illusions, that they attempt to
understand acts of tacit knowing in which we attend to something by relying on
our awareness of elements that we are not attending to in themselves
at the time. These acts might be loosely
called intuitive to distinguish them from processes of explicit reasoning, and
the inquiries I have listed can then be said to be directed towards discovering
explicit rules, the operations of which would be equivalent to these intuitive
actions. These rules would have both to
specify the particulars on the awareness of which intuition relies for
attending to a comprehensive entity formed by them, and to spell out the
integrative relations by which the particulars form such entities.
If such formalization of tacit knowing were possible,
it would convert all arts into mathematically prescribed operations, and thus
destroy them as works of art. The
analysis of art can be profoundly revealing, but only if it remains incomplete.
It must limit itself to the discovery of
maxims, the application of which is itself a work of art. However greatly it may profit from
incorporating a skeleton of such maxims, the originally tacit act will still
remain tacit, for it will rely on a subsidiary awareness of its maxims and keep
their application under tacit control.
We can see also, accordingly, that in optical illusions,
such as that which makes us see a boy taller than a grown man, ‘unconscious
reasoning’ can serve only as the kind of rule which leaves open important
alternatives to be decided by a tacit act of the subject. Instead of the premise “all rooms are rectangular
parallelepipeds,” which leads to the conclusion that a young boy can be taller
than a grown man, we could use the premise “young boys are smaller than grown
men,” and reach the conclusion that a room can be skew-angled, which would
dissolve the illusion and thus show that its formalization as of unconscious
reasoning does not explain why the eye prefers to see the illusion.
The reason for this preference lies in the fact that
we irresistibly see the room as having a normal shape. Our subsidiary awareness of a great many
normal rooms presents itself to us in terms of our seeing the room in this way.
Most of these rooms cannot be
identified. We cannot remember more than
a few of the thousands of regular shaped rooms that we have seen in the past. Yet it is the joint weight of these memories
at the back of our mind that is effective, as is shown by the fact that
primitive people who have seen fewer normal rooms are less susceptible to this
kind of illusion. [12] Moreover,
an undefinable
12. Cf. G. W. Ailport and T. F. Petigrew, J. Abn. Soc. Psych. 55, 104 (1958).
range of external clues can destroy the
illusion. For example, if we are allowed
to tap the wall of the room with a stick, at some point the cumulative effect
of such clues will cause the skew room to emerge and the illusion to be
destroyed.
This exemplifies the rival attraction of two alternative
ways of seeing a system of clues. The
one which preponderates over the other for any particular configuration,
may be said to be more readily integrated, or otherwise preferred, by the
observer. Gestalt psychology has
attempted to define the qualities of a figure which facilitate its integration,
but my present paper will not go into this question. I merely accept it, for example, that
integration can be destroyed by focusing attention on the individual particulars
and that this is favored by certain ways of looking at the integrated whole,
e.g., from very near.
More
about this later.
The process by which the conception of a normal room
is formed here, and a particular object identified as an instance of it, bears
on an ancient problem of philosophy, the elucidation of which will throw
further light on the powers of tacit integration and the limit set to a
formalization of these powers.
Plato was the first to be troubled by the fact that in
applying our conception of a class of things, we keep identifying objects that
are different from each other in every particular. If every man is clearly distinguishable
from another and we yet recognize each of them as a man, what kind of man is this,
as which all these men are recognized? He
cannot be both fair and dark, both young and old, nor
brown, white, black, and yellow at the same time; but neither can he have any
one of these alternative properties, nor indeed any particular property whatever.
Plato concluded that the general idea of
man refers to a perfect man who has no particular properties, and of
whom individual men are imperfect copies, corrupted by having such properties.
That something so utterly
featureless as the concept of man should have such a perfectly characteristic
nature, presents great difficulties which have occupied philosophers ever since
Roscelinus raised them close to 900 years ago. But his own view, that the word ‘man’ is but
the name for a collection of individual men, leaves open the question how we
can justify the labelling of a collection of
different individuals by the same name - a question that is further accentuated
by our expectation that we shall yet be able to subsume under this label future
instances of men differing in every particular from any man thus labeled
before. The difficulty is not eliminated
by specifying the characteristic features of man, since in doing so we must
again repeatedly use one name for instances of a feature that are different in
every particular.
All these difficulties arise only because we are
seeking an explicit procedure for forming collections of objects which
can be justifiably designated by the same universal term. Let us watch instead the way in which
perception identifies certain objects according to their nature. The illusion of seeing a skew room as normal
should remind us of the fact that in thousands of other cases we have correctly
seen normal rooms as such, however different each was from the other, and
however different the angles were under which we saw any particular room at a
particular moment. It also demonstrates
that the identification of particular things goes on without naming them, which
is confirmed by the fact that animals readily identify members of a class,
though they have no language. What is at
work here is a process, common to all manner of perception, in which we rely on
our awareness of a great many clues to which we are not attending at the time,
for seeing things in a particular way which is the meaning of these clues
comprehended by us.
We must note here that the problem of how a universal
concept is formed is part of the problem of empirical induction. All attempts to formulate strict rules for
deriving general laws from individual experiences have failed. And one of the reasons is again, that each
instance of a law differs, strictly speaking, in every particular from every
other instance of it. Such indeterminately
variable experiences can indeed be subsumed under the same law only by relying
on our awareness of them as clues to it. And just as for perception, many clues of
empirical induction will be easily identified in themselves, while many will
not be, and not all of them can be, identified. In other words, the scientist’s “hunches” may
be based to a greater part on subception. And just as a keen eyesight enables one to
discriminate objects that others cannot see, so does a gift of scientific discovery
reveal natural laws in a scientific experience, which signifies nothing to
others not so gifted. Those who insist
on finding a formal procedure of induction, would
reject the acknowledgment of such powers of discovery, as mysterymongering.
Yet these powers are not more mysterious
than our powers of perception but, of course, not any less mysterious, either.
But am I not, in fact, disposing of an enigma by postulating a miracle?
Not altogether. I am interpreting the formation of class
concepts (along with the discovery of natural laws) as based ultimately on a precess of tacit knowing, the operations of
609
which I have exemplified in the learning of skills, the recognition of
physiognomies, the mastery of tests, the use of tools, the uttering of speech,
and the act of visual perception. The
powers of integration which achieve these acts have the same structure
throughout. And I believe that it can be
shown, though this lies beyond the scope of this paper, that they are all
variants of the same organismic process.
Two points concerning the formation of concepts
require special attention. First, we are
assuming here that our integrative powers can resolve the apparent
contradiction involved in taking an aggregate of objects which differ in every
particular, to be nevertheless identical in some other way. Is there any evidence that tacit knowing can
establish a uniform meaning for clues, which, regarded in themselves, have
nothing that is the same in them? The
answer is that tacit knowing can in fact integrate conflicting clues in various
ways. In the Ames experiment the sight
of a boy and a grown man contradicts the distance of their heads from the
ceiling of the room, and perception integrates these contradictory clues by
presenting the boy as taller than the man. This solution is admittedly illusory; but
there is an important case when conflicting visual clues are integrated to a
true sight. We fuse the two different
pictures of an object cast on the retina of our eyes by forming its
stereoscopic image. Here perception resolves
a contradiction by revealing a joint meaning of conflicting clues in
terms of a new quality. A similar
synthesis is achieved when we hear a sound as coming from a definite direction
by combining its impacts that reach first one ear and then the other. This is also what happens in the formation of
a general conception.
But there is also an important difference, which faces
us as the second point to which we must attend. It lies in the curiously unsubstantial
character of the joint meaning ascribed to a group of objects by a general
term. Compared with optical illusions or
stereoscopic images, general conceptions are abstract, featureless. The focus in terms of which we are aware of
the members of a class appears vague and almost empty. We may ask whether there are other instances
of tacit knowing of a similar structure. The question brings up yet another traditional
problem of philosophy the clarification of which will help to consolidate and
elaborate further the conception of tacit knowing.
I have said that when we are attending to the joint
appearance of the particulars composing a man’s physiognomy, we are attending
to his person, and that when we watch the mood expressed by his face, we are
watching his mind at work in his face. Two things are apparent here. First, that tacit knowing may penetrate its
object in stages. We may first recognize
a man, then discover what he is doing, then again realize what his motives
might be, and eventually reconsider our conception of his personality. An aspect apprehended by the integration of
elementary particulars thus becomes, in its turn, a clue to a more
comprehensive entity, and so on. I have
also hinted that we thus gradually penetrate to things that are increasingly
real, things which being real, may yet manifest itself on an indeterminate
range of future occasions.
I can only deal briefly here with this analysis of the
mind, which I have carried out at some length elsewhere. It should illustrate here the fact that, as we
move to a deeper, more comprehensive, understanding of a human being, we tend
to pass from more tangible particulars to increasingly intangible entities: to
entities which are (partly for this reason) more real: more real, that is, in
terms of my definition of reality, as likely to show up in a wider range of
indefinite future manifestations.
The time sequence used for this description must not
be taken literally. We usually take in
all levels of a person to some extent straight away. We certainly recognize a human face at first
sight and can say only from a subsequent analysis, and then rather inadequately,
by what particulars we recognized it . If we could
ever see the fragments of a face without realizing their coherence as parts of
a face, we could not distinguish them from other things around them. This is actually true for any object and is
more easily demonstrable for other objects than human faces. An object becomes invisible if its particulars
cannot be picked out against a distinctive background, as for example, when it
is camouflaged. We then see the
particulars of the object, but do not know which of them belong to the object
that we do not see and may not even know about.
The position thus reached shows the impossibility of behaviorism. It follows from it that we can identify
tangible manifestations of mental processes only by first recognizing the mind
at work in them; that in fact a rational pattern of behavior must be
comprehended as a whole, before we can set out to analyze it; and finally, that
if we did succeed, per impossibile, in keeping
track of the elements of mental behavior without reference to mind, these
particulars, observed in themselves, would remain meaningless, and experiments
conducted with these meaningless fragments would also be meaningless. The actual practice of behaviorist
experimental
psychology is rescued from this fate, by
tacitly relying on the mental interpretation of its observations, which are
then translated into an objectivist language.
The present analysis also differs from that of Ryle [13] by the
distinction of two kinds of knowing. If,
as I suggest, we know the mind by relying on our awareness of its workings for
attending to their joint meaning, then Ryle’s
conclusion that the workings of the mind are the mind, is like saying
that the word ‘table’ is a table.
What I have said about the mind also bears on the
theory of phenomenalism. This doctrine teaches us to look upon
sense data as our ultimate information about the outside world, and to regard
our knowledge of the objects to which sense data refer, as based on inference
from these data. This gives rise to the
insoluble problem of the manner in which such inference can be carried out.
The school of linguistic analysis
disposed of this problem by affirming that we never perceive sense data as
such, but are aware of them only as the qualities of objects, which are
what we actually do perceive. This view,
however, fails to account for the fact, demonstrated by the experiments on apes
brought up in the dark, that learning to see needs considerable time and
effort; a fact confirmed for human infants by observations on their eye movements.
Before they learn to see objects, both
apes and babies do in fact see sense data, that is, patches of light and color.
And this is the case also when normal adults
observe the meaningless fragments of a puzzling sight and have to make an
intelligent effort in order to see the objects of which these are the
qualities.
Such an effort is a process of tacit integration by
which the object is recognized as the meaning of the sense data which
constitutes its appearance. It is not a
process of explicit inference, and hence the question of the ways in which such
inference can be conducted does not arise. The same is true for the insoluble question of
the way in which the existence of other minds is inferred. It does not arise; for we know other minds,
not by explicit inference, but by a tacit process of integration. This solution of the problem of other minds
differs from that proposed by Strawson, who shows by
linguistic analysis, that the doubting of the existence of other minds is
self-contradictory. [14] This
proves that modern usage implies belief in other minds. But in the language of Azande
it is self-contradictory to doubt the efficacy of oracles, and this only proves
that Zande language cannot be trusted in respect of
oracles. [15]
The view of our knowledge of solid objects and of a
person’s mind, as the meaning of their particulars, restores the metaphysical
notion of common sense, which speaks of things and a person’s mind as distinct
from the clues by which they happen to manifest themselves to the observer. And the same can be claimed then for
universals: They are the joint meaning
of things forming a class. This meaning
is something real, for, to repeat my phrase, it is capable of yet manifesting
itself indefinitely in the future.
It has, indeed, an heuristic
power that is usually twofold. (1) A
universal concept usually anticipates the occurrence of further instances of
itself in the future, and if the concept is true, it will validly subsume these
future instances in spite of the fact that they will unpredictably differ in
every particular from all the instances subsumed in the past. (2) A true universal concept, designating a
natural class, for example a species of animals, anticipates that the members
of the class will yet be found to share an indefinite range of uncovenanted properties; i.e., that the class will be found
to have a yet unrevealed range of intension.
This illustrates the most striking powers of tacit
knowing, owing to which we can focus our attention on the joint meaning of
particulars, even when the focus to which we are attending has no tangible
center. It represents our capacity to
know a problem. A problem designates a
gap within a constellation of clues pointing towards something unknown. If we
13 Gilbert Ryle, The
Concept of Mind (Barnes and Noble, Inc., New York, 1950).
14. F. Strawson, Individuals. An Essay in Descriptive
Metaphysics (Humanities Press, Inc., New York, 1959), p. 107. The argument is based here on the special
character of ‘P. predicates’, i.e., predicates referring to
persons. “For just as there is not in
general one process of learning... an inner private meaning of predicates of
this class, then another process of learning to apply such predicates to others
on the strength of a correlation, noted in one’s own case with certain forms of
behavior, so - and equally - there is not in general one primary process of
learning to apply such predicates to others on the strength of behavior
criteria, and then another process of acquiring the secondary technique of
exhibiting a new form of behavior, viz., first-person P.-utterances.” The author then goes on to warn that one must
not couch one’s rejection of this structure in the language of that structure.
15 E. E. Evans-Pritchard, Witchcraft, Oracles and
Magic among the Azande, (Oxford University Press,
New York, 1937). “Let the reader consider any argument that
would utterly demolish all Zande claims for the power
of the Oracle. If it
were translated into Zande modes of thought it would
support their entire structure of beliefs” (page 319). “They reason excellently in the idioms of
their beliefs but they cannot reason outside or against their beliefs because
they have no other idiom in which to express their thoughts” (p. 338). Mr. Strawson would
rightly conclude that belief in poison oracles is part of Zande
metaphysics, which can be descriptively studied in the logical structure of
their language. But this would show only
that Azande would have to use a different language
(or use Zande language with a new meaning) if they
wanted to repudiate their present metaphysical beliefs.
611
hold a problem to be a good one, we also imply
that this unknown can yet be discovered by our own efforts, and that this would
be worth these efforts. To undertake the
search for the solution of a problem is to claim the faculty of sensing the
increasing proximity of its solution - since no inquiry can succeed without
such guidance. In all these anticipations,
essential to any scientific endeavor, we focus our attention on a center that
is necessarily empty.
This brings into sight once more the process of
empirical induction. I have noted the heuristic powers of a true universal
conception, and have now consolidated the idea of such powers by pointing out
our capacity to recognize problems, to know good problems from bad ones, and to
pursue these successfully, by feeling our steady approach to their solution. The work of the scientist consists in doing
all these things. He notices clues that
seem significant, and, if he is an experimenter, tries to turn up new clues
that would give him further guidance. All the time his attention is fixed on the
meaning of the clues he has collected so far, while he is feeling his way
towards new ideas and new evidence, by following his sense of approaching
discovery. This procedure does not
essentially differ from that of perception, to which I have affiliated it. Any sustained effort to make out what confronts
us in a confusing configuration of sights, is an exercise of similar powers of
searching for clues by sensing the nearness of a significant shape to which
they might tend to crystallize.
I have said that the capacity to know a problem is the
most striking instance of our powers to integrate the meaning of a set of
particulars by fixing our attention on a gap behind which we anticipate the
presence of yet hidden knowledge. Before
developing this further, let me recall that we had already recognized these
heuristic powers in a less dynamic form wherever we rely on our awareness of
particulars for establishing the presence of a comprehensive entity. For this was always viewed as something real,
which being real, might be expected yet to manifest itself at some future time
in unexpected ways. I have shown how
this confirmed in its own way the common sense metaphysical belief that solid
objects were something beyond the aggregate of their observed properties and that
the mind is something beyond its overt manifestations; I have also shown that
this conception of meaning reveals the thing that is named by a universal term.
But it is still the course of scientific
inquiry in which the metaphysical conception of a reality beyond our tangible
experience is written out most clearly, for all to see. From its very start, the inquiry assumes, and
must assume, that there is something there to be discovered. The fascination, by which alone the inquiry
can make progress, is fixed on discerning what it is that is there, and when
discovery is achieved, it comes to us accredited by our conviction that its
object was there all along, unrecognized. The rise, the path, the end,
all point at the same reality and cannot but tell of it. Swearing by the existence of this reality, the
scientist imposes on himself the discipline of his vocation. And his sense of approaching nearer to reality
is not exhausted by the consummation of discovery. It persists in the belief that what he has
discovered is real, and being real, will yet mark its presence by an unlimited
range of unsuspected implications. Deemed
to be an aspect of reality, the new knowledge is believed to be fruitful and is
claimed to be universally valid.
Here we meet the conception of truth. Modern antimetaphysical
philosophies, like pragmatism, operationalism,
positivism, and logical positivism, have tried to spell out the implications of
asserting a proposition to be true. But
if the truth of a proposition lies in its bearing on reality, which makes its
implications indeterminate, then such efforts are foredoomed. They have in fact failed, and must fail, for
the indeterminate cannot be spelt out without making it determinate. It can be known in its indeterminate condition
only tacitly, by those tacit powers by which we know more than we can tell.
The antimetaphysical analysis of science
assumes that the logical foundation of empirical knowledge must be capable of
definition by explicit rules. While the
difficulties of this enterprise have not gone unnoticed, the reluctance to
abandon it in principle still seems universal. My attempts to acknowledge tacit powers of
personal judgment as the decisive organon of
discovery and the ultimate criterion of scientific truth,
have been opposed, by describing these agencies as psychological, not logical,
in character. But this distinction,
going back to Kant’s separation of the phenomenal from the noumenal,
is not explained by my critics. Is an
act of perception which sees an object in a way that assimilates it to past
instances of the same kind, a psychological process or a logical inference? We have seen that it can be mistaken and its
results be false; and it certainly has a considerable likelihood of being true.
To me this suggests that it is a logical
process of inference even though it is not explicit. In any case, to perceive things rightly is
certainly part of the process of scientific inquiry and to hold perceptions to
be right, underlies the holding of scientific propositions
to be true. And if, in consequence, we
must accept
the veridical powers of perception as the
roots of empirical science, we cannot reasonably refuse to accept other tacit
veridical processes having a similar structure. This is what I have been urging all along
since I first wrote “... that the capacity of scientists to guess the presence
of shapes as tokens of reality, differs from the capacity of our ordinary
perception only by the fact that it can integrate shapes presented to it in
terms which the perception of ordinary people cannot readily handle.” [16] And this is what I have
tried to elaborate also in my present paper. [17]
Part III: Primary
& Secondary Qualities
This concludes the philosophic survey set in motion by
pondering the strange fact that the experience of our senses is somehow to be
accounted for in terms of neural processes within our body. In conclusion, I shall deal now with the
general context of the distinction between primary qualities representing the
objective reality of all things and secondary qualities deemed to be
subjective. Galileo’s vision of a
universe consisting ultimately of masses in motion, has ruled the minds of
scientists and philosophers until the end of the nineteenth century, when it
was first seriously modified within physics itself by the discovery of the
electrical character of ultimate particles. Today we would have to regard as the primary
qualities of the universe the parameters (statistical functions) determined by
physics, and to ask how these give rise to the additional qualities of colors,
sounds, tastes, and smells by means of a particular configuration of these
parameters within the nervous system.
However, it will be simpler, and involve no loss of generality, if I set out the Laplacean vision in terms of its original model of primary qualities consisting of the masses, positions, velocities, and forces of ultimate particles. Laplace declared that the prediction of this configuration for the universe would supply us with a knowledge of “all things to come.” It was always agreed that we were technically incapable of establishing the initial configuration on which to base such calculations and that we could not possibly carry out these calculations even if we knew the original configuration. But it has never been doubted that if we were presented with the complete atomic configuration of the universe at any moment, we would know about it everything that we might conceivably want to know. This is what I shall contest here.
The law of irreversibly increasing entropy governs the fundamental processes of equilibriation in nature. But the entropy of a system cannot be computed from a knowledge of its atomic configuration, for it is measured by the extent to which this configuration is uncertain. This argument can be made more definite by assuming quantization. The entropy of a precisely known atomic configuration is, then, zero and remains zero throughout the future; equilibriation by increasing entropy does not take place. We can have equilibriation only if we introduce conceptions of probability, by assuming that the configuration of atoms is to a considerable extent uncertain.
We meet with the same kind of situation wherever we assess chances. If, in throwing dice, we know the exact physical particulars of our throws and hence could predict their outcome, the probability of any particular sides of the dice turning up would be inconceivable, and no actions based on such probabilities (e.g., betting) could be justified. Even so in physics, if all atomic particulars were specified, processes governed by probabilities, e.g., irreversible equilibriations, would be inconceivable and their actual occurrence could not be accounted for. We may regard, therefore, such processes as comprehensive features, which disappear when their particulars are specified in terms of a Laplacean topography.
This illustrates the logical deficiency of the Laplacean conception of universal knowledge at an elementary level. It faces us, more generally, in the fact that questions in which we are interested arise in the context of experiences which do not consist in atomic configurations, and which may not be derivable from the conceptual framework of atomic configurations.
Let me illustrate this further by the example of machines. Machines are solid structures made up of several parts, which have their several functions in the operation of the machine. Thus a machine can be described as a particular configuration of solids. The description would state the materials and shapes of the parts, and the boundary conditions by which they are joined together as a system. But this could describe only one particular specimen of one kind of machine. It could not characterize a class of machines of the same kind, which would include specimens of different sizes, often of different materials, and with an infinite range of other variations. Such a class would be truly characterized by the operational principles of the machine, including the principles
16. M. Polanyi, Science, Faith and Society (Oxford University
Press, New York), p. 10.
17. I would emphasize at this point once more that the origin of the
veridical powers of tacit integration lies beyond the scope of this paper; I am
concerned here only with defining their structure and illustrating their range.
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of its structure. It is by these principles, when laid down in
the claims of a patent, that all possible realizations of the same machine are
legally covered; a class of machine is defined by its operational principles.
What conceptions, if any, are introduced here that
cannot be derived from an atomic topography? Let us suppose, for the sake of simplifying
the argument, that the difficulties of deriving the laws of physics and
chemistry from a Laplacean knowledge of the world’s
atomic configuration can be overcome. We
may observe then (1) that a particular specimen of a machine is characterized
by the nature of its materials, by the shape of its parts and their mutual
arrangement, which can be defined by the boundary conditions of the system, [18] and (2) that the laws of physics and
chemistry are equally valid for all solids, whatever their materials and
shapes, and the boundary conditions determining their arrangement. From which it follows that neither the
materials nor the shapes of the solids forming part of a (particular) machine,
nor their arrangement, can be derived from physics and chemistry. And that hence physics and chemistry cannot
account for the existence of a machine, cannot even identify a machine as a machine,
and still less identify its workings and account for these.
This limitation becomes clearer if we consider a class
of one type of machine, for example, steam engines. Such a class, could
be effectively covered by a patent or be referred to in a trade agreement. The description of the principles on which
steam engines are constructed and operated would enable a court of law to
decide whether an object is a steam engine or not, and even to identify damaged
engines that do not work. In order to
account for the existence of such a class in terms of physics and chemistry, it
would be necessary to derive from the laws of physics and chemistry a general
relationship of materials and shapes of a group of solids, of their mutual
arrangement, given by the boundary conditions of the system, and their purpose,
which would jointly characterize all objects that are steam engines, even when
broken down.
In order to envisage this task, we shall assume that
an individual specimen of a certain type of machine has been fully described in
terms of its physical and chemical topography. The task is then to identify and generalize
such features of this topography as characterize a steam engine, including one
that has broken down. The laws of
thermodynamics will of course be referred to in any such generalization. But these laws do not define the steam engine:
A steam engine is something that relies
on these laws for its workings. To
define a steam engine is to tell in what way it utilizes the laws of
thermodynamics and other laws of physics and chemistry. Any principles utilizing the laws of physics
and chemistry are compatible with these laws, and therefore no special set of
these principles can be derived from physics and chemistry. That is why these principles are part of a
distinctive science, the science of engineering. Engineering deals with principles of technical
success, and hence can also identify technical failure, as in broken down steam
engines.
It follows that even if physics and chemistry could be
derived from predictions of atomic topography, the existence of the machines
could not be stated, let alone accounted for, in these terms. And, accordingly, the knowledge of engineering
(as defined above) and of all problems of engineering, as well as of inventions
and arguments conducted in terms of engineering, would be absent in a knowledge
of the physical and chemical topography of the universe, and, a fortiori, in
its atomic topography.
The nature of this limitation is logical. Its reasons are of the same kind as those for
which physics and chemistry cannot identify a printed page (even though
printing relies on the laws of physics and chemistry), nor tell us what the
print says.
I have argued this conclusion extensively, as much because of its
general significance, as for its particular bearing on biology. Physiology is the study of the operational
principles by which living things survive and propagate themselves. There is some difference of opinion today
whether all living functions are machine-like; the predominant view is
that they are all machine-like. I am not
concerned here with the question whether or not this view is true; my argument
bears on the unanimous view, held by both sides of the controversy, that
the machine-like explanation of physiological functions is equivalent to their
explanation in terms of physics and chemistry. My demonstration that machines cannot be
accounted for in terms of physics and chemistry applies equally to the machine-like
operations of animals. I must conclude,
therefore, that to equate any machine-like explanation with an explanation in
terms of physics and chemistry is a logical absurdity. This does not
18. The purpose served by a device may also be decisive for its
identification. Some years ago Phillips
(Eindhoven) and United Incandescent Lamps (Ujpest) were in conflict about the question whether the
newly invented sodium discharge lamps were to be classed as ‘neon lights’ under
an agreement to which both firms were parties. An important point made for not classing
them thus, was that sodium lights are used for seeing by them and neon
lights for being seen.
mean that these mechanisms could not have come
into existence phylogenetically by processes of physics
and chemistry. I myself do not think
this is possible, but physiology is not a theory of evolution, and I do not
include evolution in my conclusions here, any more than physiologists do, when
saying that they are explaining physiological functions in terms of physics and
chemistry.
Let me return then to my general argument. The Laplacean
conception of universal knowledge, which is but a particular illustration of
the theory of primary qualities on which science has been based since Galileo,
has always been thought to require a superhuman mind capable of collecting the
initial data and then calculating future atomic constellations. But it has been consistently overlooked that
at this point the universal mind meets with more fundamental difficulties. I believe that I have shown (1) that there is
no evidence to suppose that the “universal knowledge” conceived by Laplace would answer any questions that we are interested
in; (2) that to find out the entropy, temperature, and pressure of a system from
a Laplacean universal knowledge requires estimates of
probability, a conception not derivable from an atomic topography; (3) that all
engineering and technology comprising operational principles lies logically
beyond the range of Laplacean knowledge; and (4) that
the same is true for the operational principles established by physiology as
the functions of living things.
The list could be extended indefinitely. An obvious case to be added would be the
impossibility of accounting for sentience in terms of the primary qualities
defined by physics. But enough has been
said to substantiate a general conclusion in terms of the principles of tacit
knowing explained in this paper. Atomic
configurations are the ultimate particulars assumed to be underlying all the
manifestations of more comprehensive entities in the universe. We have seen that the particulars of such
entities lack the meaning which the entities possess. Consequently when we focus our attention on
the ultimate particulars of the universe we are facing things which have the
least possible meaning. A Laplacean mind that would compute from the present
virtually meaningless atomic topography of the world its future similarly
meaningless topography, would not materially advance our knowledge of the
world, let alone represent a universal knowledge of it.
The world could be known from such a
topography only if we had the power to integrate it by an act of tacit
knowing. But such powers are far from unlimited.
The integration produced in the Ames experiment
with the skew room, is irretrievably lost by looking at the arrangement from a
“forbidden angle.” There is a well known
guessing game which makes use of the fact that photographs taken from an
unusual angle make familiar objects unrecognizable. The full range of colors produced according to
Land, by super-imposing two monochromatic optical images, disappears when we
look at the two components separately. All
patterns vanish if we scan them through a sufficiently strong magnifying glass.
(I repeat that these limits of our
integrative powers are accepted in this paper as facts, without enquiring into
their origin).
This should suffice to explain the obvious facts that
no human intelligence could apprehend, by looking at an atomic topography of a
frog, that it is a frog, nor understand from the frog’s
computed future topographies, the physiology of a frog. And, of course, what is true for its atomic topography, is equally true for a physical-chemical
topography of the frog; we could perceive in it nothing of the frog.
If we could rely on our awareness of the data forming a topography for attending to their joint meaning, the
topography would become transparent, in the same sense as a text is transparent
when we read and understand it. But
since this is not possible, it can only block our view by its meaningless body
- even as a text does, when we concentrate our attention on its physical
details.
When one reaches the conclusion that an assumption
widely taken for granted during a long time is patently false, one asks
oneself, how such an error could have arisen and been perpetuated. The answer in this case is not far to seek. The Laplacean conception of universal knowledge, as well as its modern
equivalents, are models of a completely formalized, or mathematical,
representation of the universe. And ever
since the middle of the eighteenth century, science has inflexibly set itself
the ideal of casting all knowledge into mathematical form. Descriptive sciences were to be regarded as
imperfect, immature branches of knowledge, that would
sometime be replaced by definitive mathematical formulations.
But this ideal is logically absurd. Imagine a set of mathematical formulas that
would answer any questions that we might ask about matters of experience. The object of such experience must be other
than the mathematical formulas which are to explain it and hence these formulas
are meaningless unless they bear on non-mathematical experiences. In other words, we can use our formulas only
after we have made sense of the world to the point of asking questions about it
and have established the bearing of
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the formulas on the experience that they are
to explain. Mathematical reasoning about
experience must include, beside the antecedent non-mathematical finding and
shaping of experience, the equally non-mathematical relating of mathematics to
such experience and the eventual, also non-mathematical, understanding of
experience elucidated by mathematical theory. It must also include ourselves,
carrying out and committing ourselves to these non-mathematical acts of
knowing. Hence a mathematical theory of
the universe claiming to include its own bearing on experience would be self
contradictory in the same sense as the conception of a tool would be if the
tool were described as including its own user and the things to which it was to
be applied.
Knowing is a process in two stages, the subsidiary and
the focal, and these two can be defined only within the tacit act, which relies
on the first for attending to the second. But again, why should this fact have been
overlooked and a false ideal of science been perpetuated for centuries? Because the moment we admit that all knowing
is rooted in an act of personal judgment, knowledge seems to lose all claim to objectivity. I have hinted at a way out of this difficulty
by my definition of reality, and a substantial treatment of it has been given
elsewhere. But the answer will yet have
to be worked out fully in the future.
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