with that view of them which I endeavoured to give you, in a former
lecture, are not digressive now, nor uselessly repeated. It is of great
importance for the applications which we have to make, that you should
be fully aware that our muscular frame, is not merely a part of the
living machinery of motion, but is also truly an organ of sense. When I
move my arm, without resistance, I am conscious of a certain feeling;
when the motion is impeded, by the presence of an external body, I am
conscious of a different feeling, arising partly, indeed, from the
mere sense of touch, in the moving limb compressed, but not consisting
merely in this compression, since, when the same pressure is made by
a foreign force, without any muscular effort on my part, my general
feeling is very different. It is the feeling of this resistance to our
progressive effort, (combined, perhaps, with the mere tactual feeling)
which forms what we term, our feeling of solidity or hardness; and,
without it, the tactual feeling would be nothing more, than a sensation
indifferent or agreeable, or disagreeable or severely painful,
according to the force of the pressure, in the particular case; in
the same way, as the matter of heat, acting, in different degrees, on
this very organ of touch, and on different portions of its surface, at
different times, produces all the intermediate sensations, agreeable,
disagreeable, or indifferent, from the pain of excessive cold, to the
pain of burning; and produces them in like manner, without suggesting
the presence of any solid body, external to ourselves.
Were the _cube_, therefore, in the case supposed, pressed, for the
first time, on the hand, it would excite a certain sensation, indeed,
but not that of resistance, which always implies a muscular effort
that is resisted, and consequently not that of hardness, which is a
mode of resistance. It would be very different, however, if we fairly
made the attempt to press against it; for, then, our effort would be
impeded, and the consequent feeling of resistance would arise; which,
as co-existing in this case, and in every case of effort, with the
particular sensation of touch, might afterwards be suggested by it, on
the simple recurrence of the same sensation of touch, so as to excite
the notion of hardness, in the body touched, without the renewal of any
muscular effort on our part, in the same manner as the angular surfaces
of the cube, if we chance to turn our eye on it, are suggested by the
mere _plane_ of _colour_, which it presents to our immediate vision,
and which is all that our immediate vision would, of itself, have
made known to us. The feeling of resistance, then, I trust, it will
be admitted, and consequently of hardness, and all the other modes of
resistance, is a muscular, not a tactual feeling.
But though the resistance or hardness of the cube, as implying some
counter effort, may not be immediately sensible to our superficial
organ of touch, are not its dimensions so perceived? Its cubical form,
it will be allowed, cannot be felt, as only one of its surfaces is
supposed to be pressed upon the hand; but, is not at least this square
surface perceived immediately? In short, does not touch, originally and
immediately, convey to us the knowledge of extension?
With our present complete belief of external things, indeed, and
especially of our organs of sense, the most important of these,
the origin of our knowledge of extension, seems to us a matter of
very easy explanation. The square surface presses on our organ of
touch,--it affects not a single physical point merely, but a portion
of the organ, corresponding exactly, in surface with itself; and the
perception of the similar square, it will be said, thus immediately
arises. But, in all this easy explanation, it is very strangely
forgotten, that the _feeling_, whatever it may be, which the impression
of the square surface produces, is not itself the square configuration
of our tactual organ, corresponding with that surface, but the state
of a very different substance, which is as little square, as it
is round or elliptical,--which is, indeed, from its own absolute
simplicity, incapable of resemblance in shape to any thing; and the
resemblance of which, therefore, to the shape of the mere organ, is
as little to be expected in the sensations of touch,--as that other
state of mind, which constitutes the sensation of the fragrance of a
rose, can be expected to resemble the shape of the odorous particles
themselves, or of the organ of smell, which is affected by them. The
very knowledge which touch is supposed to give, is, in this case, most
inconsistently, assumed, as existing in the mind, before the very touch
which is supposed to give it. If, indeed, the mind could know, that a
part of its external corporeal organ is compressed into the form of a
square, or that another square surface is compressing that organ, the
difficulty would be at an end; for it would, then, most undoubtedly,
have that very knowledge of extension, the origin of which we seek. But
it is not explained, _how_ the mind, which alone can have sensation
or knowledge, and which certainly is not square itself, is to be made
acquainted with the squareness of its own corporeal organ, or of the
foreign body; nor, indeed, how the squareness of the mere external
organ should produce this particular affection of the mind, more
than if the organ were compressed into the shape of a polygon of one
thousand sides.
Let it be supposed, that, when a small cube is pressed on the hand,
one hundred physical points of the organ of touch are affected in a
certain manner. We have, it is said, an immediate perception of a
square surface. Let it next be supposed, that, instead of one hundred
of these continuous points of the organ, an equal number of points,
at various distances in the surface of the body, are affected in the
same manner. On this supposition it will scarcely be said, that the
perception of a square would arise, when there is no square, more
than any other imaginable form, in the space comprehended in the
pressure. Yet what difference is there, in these two cases, to a
mind that is, by supposition, absolutely ignorant of every bodily
organ, and consequently alike ignorant of the nearness or distance of
the points of the organ of touch? In both cases, one hundred points,
equally sensible, are affected, and are affected precisely in the same
manner;--and there is truly no difference, unless we tacitly suppose
the mind to be conscious of the bodily frame, and, therefore, of the
continuity of certain points of the organ of touch, with the other
points that are proximate to them,--a sort of knowledge, for which it
would not be easy to account, and which it is impossible to conceive,
without conceding the very point in question. A little attentive
reflection on the circumstances of these two cases, will, perhaps, aid
you in freeing your minds from the illusive belief, of which it may not
be easy for you at first to divest yourselves,--that the continuity and
similarity of shape, which are known to _us_ the inquirers, are known
also to that little sentient being, whose first elements of knowledge
we are endeavouring to trace.
We are too apt to forget, in inquiries of this sort, that it is not
in our organ of touch merely, that a certain extent of the nervous
extremity of our sensorial organ is affected. This occurs, equally,
in every other organ. In the superficial expansion of the nerves of
hearing, smell, taste, for example, it is not a point merely that is
affected, but a number of continuous points, precisely, as in the
superficial organ of touch; and if, therefore, the notion of extension
in general, or of figure, which is limited extension, arose whenever a
part of the nervous expansion was affected in any way, we should derive
these notions as much from a taste, or a smell, or a sound, as from any
of the configurations or affections of our organ of touch.
It is not, therefore, merely because a certain limited part of the
sensorial organ is affected, that we have the notion of the square
surface, in the case supposed by us: for, if this alone were necessary,
we should have square inches, and half inches, and various other forms,
rectilinear or curvilinear, of _fragrance_ and _sound_.
But, it may perhaps be urged, though all our organs must, indeed, exist
equally with our organ of touch of a certain shape when affected,--and
though the sensorial figure of our other organs, is not accompanied
with any of those mental affections, which constitute the perception
of angular or curvilinear figure, there is something, in the nature
of that part of the sensorial organ, which terminates on the general
surface of the body, that impresses the mind, immediately, with a
sensation, corresponding with the exact figure, in which the organ may
itself exist. When the _square_, therefore, in the case imagined by us,
is impressed upon the organ, the mental affection which constitutes our
notion of a square may immediately arise, though it would not arise
from the similar squareness of our organs of smell or hearing.
In answer to this mere supposition, I may remark, that the sensorial
organ of touch exists, at every moment, of a certain shape, and that
we yet have no perception of this shape, so as to be able to delineate
the whole extent of our _tactual_ organ, in the same manner as we could
delineate the impressing square, in the case supposed: or, if it be
said, that the configuration of the organ does not excite this mental
affection, in the quiescent state of the part, but only when it is
itself affected, I may remark, that we are as little able to delineate
its figure, when we are exposed to the action of heat, which yet acts
most powerfully upon this very organ, inducing sensations, at least as
vivid as those of hardness or figure.
It may still, however, be contended, for in a question of this sort
I wish fairly to imagine every possible argument--it may still be
contended, that, though the organ of touch has no effect, in this way
merely as configured, and might, in any other configuration operate,
precisely in the same manner, on the sentient mind,--still the harmony
of the bodily and mental changes is so arranged by nature, that the
organic state in touch, whatever it may be, is immediately followed
by the knowledge of the extension of the impressing body,--in the
same manner as a certain state of the organ of _smell_, whatever that
state may be, is immediately followed by that affection of the mind,
which constitutes our sensation of the fragrance of a rose. Though
this argument, in truth, rather begs the question, than attempts to
meet it, let us give to it all the force which it may claim. The
accurate determination of the point may, indeed, seem, at first almost
impossible; since in whatever manner the seeming perception may arise,
it must be admitted, that we now seem to perceive extension, as it were
immediately, by touch; though not more immediately than in vision we
seem to perceive the positions of objects in different distances before
our eyes.--But there is, fortunately, at least one test, which the
point in question still admits. If the apparent perception of extension
by touch, be truly and originally immediate, and not acquired, like the
apparent perception of distance in vision, so as to involve a sort of
intellectual measurement or suggestion of some sort, after the primary
sensation,--the perception must be constant and universal, not confined
to a few simple and familiar forms, which, if we can distinguish
these alone, we may be supposed to have learned from experience,
but extending to forms of every kind; for it would certainly be a
very strange abuse of the license of supposition, to imagine that we
perceive a square immediately, but not a circle, or a circle but not a
square, or indeed any other figure. Even at present, then--though the
circumstances of the trial,--when the experience of many years must
have exhausted so many varieties of form, associating the notion of
these with the particular tactual feeling whatever that may be--are
surely very unfavourable to the opinion which I maintain,--even at
present, I may safely trust to experiment, the determination of
the question. When a body which we do not see, is pressed on any
part of our tactual organ, do we immediately discover its form,--as
immediately, as we are sensible of fragrance, when our organ of smell
is in a healthy state, and an odoriferous body is presented to it, or
of sound, when a cannon is fired beside us? This we certainly should
do, if figure were as direct an object of the sense of touch, as
fragrance and sound are of the senses of smell and hearing. Even though
it be a form of the simplest kind, square, round, triangular, that is
thus pressed upon our palm, we scarcely distinguish the precise species
of figure for a moment, and are long before we can convince ourselves,
that we have perceived its exact magnitude, in the determination of
which, after all, we shall very probably be mistaken, if we confine
ourselves to the mere intellectual measurement; though we should even
add to the immediate sensation of touch, all the discriminating skill
of our judgment and reflection. But, if the body be irregular in
form,--however slight the irregularity may be, and of a species that
would not perplex in the slightest degree our sense of sight, and which
certainly, therefore, should perplex as little our sense of touch,
which is supposed to be still more immediately perceptive of form,--we
are incapable for some time, and I may even say are incapable
altogether, of fixing, with precision, its magnitude and figure--that
very magnitude and figure which are yet said to be the direct objects
of touch. Of this a single trial may convince any one; it is a trial
which as it seems to me decisive, I must request you to make. Are we
then entitled to say, in the case of the square surface of the cube
pressed upon our hand, that though we cannot discover other forms and
magnitudes, we yet discover its extension, and consequently its figure,
by the immediate sense of touch?--or may we not rather conclude with
confidence, that what is true of other forms is true of this also,
that it is only in consequence of more frequent experience we have
learned as it were to distinguish, with some degree of certainty, the
simpler forms, which, as mere forms, are not more direct objects of
the sense of touch than forms the most irregular, and that without
such experience, therefore, our mere sense of touch is incapable of
informing us of the figure of bodies, immediately and originally.
If then the knowledge of extension be not derived from our immediate
sense of touch, it must be derived from some other source, which
allows it to be associated with the feelings of touch, and afterwards
suggested by these, in the same manner as distant extent, in the case
of vision, is suggested by a few slight varieties of colour. Let us
endeavour, then, since some such source there must be, to discover what
the source is.
FOOTNOTES:
[84] Deserted Village, v. 120.
[85] Principles of Moral and Political Science, Part I. c. i. sect. i.
[86] Cowper's Task, Book IV.
LECTURE XXIII.
ANALYSIS OF THE FEELINGS USUALLY ASCRIBED TO THE SENSE OF TOUCH,
CONTINUED.
My last Lecture, Gentlemen, was employed in considering the information
which we receive from the sense of _touch_, or rather the information
which we are commonly supposed to receive from that sense,--but which,
in a great part at least, I am inclined to ascribe to another source.
The qualities of bodies, supposed to be made known to us by touch, I
reduced to _two_, of which all--whatever be the variety of names that
express them,--are mere varieties, RESISTANCE and EXTENSION:--solidity,
liquidity, viscidity, hardness, softness, roughness, smoothness,
being modes of RESISTANCE, and nothing more;--figure, magnitude,
divisibility, as evidently nothing more than modes of EXTENSION: and I
stated reasons, which induce me to believe, that neither our feeling of
resistance nor that of extension, has its direct origin in the sense of
touch; though the original simple feeling, which this organ affords, is
_now_, from constant association, almost indiscriminately combined with
both, in some one or other of their varieties.
The first of these classes,--that which includes the various
modifications of _resistance_,--I examined at great length, and
showed, I trust, that it is not to our organ of touch we are indebted
for these, but that they are feelings of another sense, of which our
muscular frame is the organ,--the feelings, in short, of which every
one must have been conscious, who has attempted to grasp any body, or
to press against it, when the full contraction of the muscles must,
of course, have been impeded. According as the body is hard or soft,
rough or smooth,--that is to say, according as it resists, in various
degrees, the progress of our effort of contraction,--the muscular
feeling, which arises from the variously impeded effort, will vary
in proportion; and we call hard, soft, rough, smooth, that which
produces one or other of the varieties of these muscular feelings of
resistance,--as we term sweet or bitter, blue or yellow, that which
produces either of these sensations of taste or vision. With the
feeling of resistance, there is, indeed, in every case, combined, a
certain tactual feeling, because we must touch whatever we attempt to
grasp; but it is not of this mere tactual feeling we think, when we
term bodies hard or soft,--it is of the greater or less resistance
which they afford to our muscular contraction.
I next proceeded to consider the other class of supposed tangible
qualities, which includes the various modifications of _extension_,
and urged many arguments to show, in like manner, that,--however
indissolubly these may seem at present to be connected with the simple
feelings of our organ of touch,--it is not to our simple original
feelings of this sense, that we owe our knowledge of them, as qualities
of things without.
Though the notion of _extension_, however, may arise in the manner
which I have supposed, this, it may be said, is not the notion of
external existence. To what, then, are we to ascribe the belief of
external reality, which now accompanies our sensations of touch? It
appears to me to depend on the feeling of resistance,--the organ
of which, as a muscular feeling, I before explained to you, which
breaking in, without any known cause of difference, on an accustomed
series, and combining with the notion of extension, and consequently
of divisibility, previously acquired, furnishes the elements of that
compound notion, which we term the notion of _matter_. _Extension_,
_resistance_;--to combine these simple notions in something which is
not ourselves, and to have the notion of matter, are precisely the
same thing; as it is the same thing to have combined the head and neck
of a man with the body and legs of a horse, and to have the notion of
that fabulous being, which the ancients denominated a _centaur_. It
certainly, at least, would not be easy for any one to define matter
more simply, than as that which has parts, and that which resists our
effort to grasp it; and, in our analysis of the feelings of infancy,
we have been able to discover how both these notions may have arisen
in the mind, and arisen too, in circumstances, which must lead to the
combination of them in one complex notion.
The infant stretches out his arm for the first time, by that volition
without a known object, which is either a mere instinct, or very near
akin to one,--this motion is accompanied with a certain feeling,--he
repeats the volition which moves his arm fifty or one thousand times,
and the same progress of feeling takes place during the muscular
action. In this repeated progress, he feels the truth of that intuitive
proposition, which, in the whole course of the life that awaits him,
is to be the source of all his expectations, and the guide of all
his actions,--the simple proposition, that _what has been_ as an
antecedent, will be followed by what has been as a consequent. At
length he stretches out his arm again, and instead of the accustomed
progression, there arises, in the resistance of some object opposed
to him, a feeling of a very different kind which, if he persevere
in his voluntary effort, increases gradually to severe pain, before
he has half completed the usual progress. There is a difference,
therefore, which we may, without any absurdity, suppose to astonish
the little reasoner; for the expectation of similar consequents, from
similar antecedents, is observable even in his earliest actions, and
is probably the result of an original law of mind, as universal, as
that which renders certain sensations of sight and sound the immediate
result of certain affections of our eye or ear. To any being, who is
thus impressed with belief of similarities of sequence, a different
consequent necessarily implies a difference of the antecedent. In the
case at present supposed, however, the infant, who as yet knows nothing
but himself, is conscious of no previous difference; and the feeling of
resistance seems to him, therefore, something unknown, which has its
cause in something that is not himself.
I am aware, that the application to an infant, of a process of
reasoning expressed in terms of such grave and formal philosophic
nomenclature, has some chance of appearing ridiculous. But the
_reasoning_ itself is very different from the _terms_ employed to
express it, and is truly as simple and natural, as the terms, which
our language obliges us to employ in expressing it, are abstract and
artificial. The infant, however, in his feeling of similarity of
antecedents and consequents, and of the necessity, therefore, of a new
antecedent, where the consequent is difficult, has the _reasoning_,
but not the _terms_. He does not form the proposition as universal, and
applicable to cases that have not yet existed; but he _feels_ it in
every particular case, as it occurs. That he does truly reason, with at
least as much subtility, as is involved in the process now supposed,
cannot be doubted by those who attend to the manifest results of his
little inductions, in those acquisitions of knowledge, which show
themselves in the actions, and, I may say, almost in the very looks of
the little reasoner,--at a period long before that to which his own
remembrance is afterwards to extend, when, in the maturer progress of
his intellectual powers, the darkness of eternity will meet his eye
alike, whether he attempt to gaze on the past, or on the future; and
the wish to know the events, with which he is afterwards to be occupied
and interested, will not be more unavailing, than the wish to retrace
events, that were the occupation and interest of the most important
years of his existence.
Then,
“So--when the mother, bending o'er his charms,
Clasps her fair nurseling in delighted arms;--
With sparkling eye the blameless plunderer owns
Her soft embraces and endearing tones,
Seeks the salubrious fount with opening lips,
Spreads his inquiring hands, and smiles and sips.”[87]
Even then, many a process of ratiocination is going on, which might
have served as an example of _strict logic_ to Aristotle himself, and
which affords results, far more valuable to the individual reasoner,
than all the contents of all the folios of the crowd of that great
logician's scholastic commentators.