sensations of warmth, to the other sensations commonly ascribed to
this organ; and the great difference of the feelings, has led some
physiologists to believe, that the organs of sensations so different,
must themselves be different. But even though the sensations were
as dissimilar as is supposed, there is no reason _a priori_ to
believe,--and to experience, it is evident, that, in this case, we
cannot appeal, so as to derive from it any ground for believing,--that
sensations, which are very different, must arise from affections
of different organs. As far, indeed, as we can safely appeal to
experience, in this very case, there are sensations which we never
hesitate in referring to our tactual nerves, as different from the more
common sensations ascribed to touch, as the sensation of warmth itself.
I allude to the pain of puncture or laceration of the skin. Indeed, if
the brain be ultimately the great organ of all our sensations, it is
evident that we must refer to affections of _one_ sensorial organ, not
the various feelings of touch only, but, with them the still greater
variety of feelings, that constitute our sensations of smell, taste,
sound, and colour.
But are we indeed sure, that there truly is that great dissimilarity
supposed, or may not our belief of it arise from our reference to touch
of sensations that truly do not belong to it? Such, at least, is the
opinion, to which, I think, a nicer analysis will lead us. The primary
original feelings, which we owe to our mere organ of touch, I consider
as of a kind, all of which are far more analogous to the sensations of
warmth, or of pain on puncture, than to the perceptions of form and
hardness, which are generally regarded as tangible. Before entering on
the analysis, however, it will be necessary to consider, what are the
sensations which we are supposed to owe to this organ.
The sensations of _heat_ and _cold_,--as received from our organ of
touch,--we may almost lay out of account in our analytical inquiry.
It is unnecessary to dwell on them, or even to repeat, in application
to them, the argument, which has been already applied more than once
to the sensations before considered. It is quite evident, that, in
classing our warmth or chillness, as a sensation,--and not as a feeling
that has arisen spontaneously in the mind,--we are influenced by
that experience, which has previously given us the belief of objects
external,--at least, of our own corporeal frame,--and that, if we
had been unsusceptible of any other sensations, than those of heat
and cold, we should as little have believed these to arise directly
from a corporeal cause, as any of our feelings of joy or sorrow. The
same remark may be applied to the painful sensations of puncture and
laceration.
It is only to the other more important information ascribed to the
sense of touch, therefore, that our attention is to be directed.
By _touch_, we are commonly said to be made acquainted with extension,
magnitude, divisibility, figure, motion, solidity, liquidity,
viscidity, hardness, softness, roughness, smoothness. These terms, I
readily allow, are very convenient for expressing notions of certain
forms or states of bodies, that are easily distinguishable. But,
though specifically distinguishable, they admit generically of very
considerable reduction and simplification. Hardness and softness, for
example, are expressive only of greater or less resistance,--roughness
is irregularity of resistance, when there are intervals between the
points that resist, or when some of these points project beyond
others,--smoothness is complete uniformity of resistance,--liquidity,
viscidity, are expressive of certain degrees of yieldingness to our
effort, which solidity excludes, unless when the effort employed
is violent. All, in short, I repeat, are only different species or
degrees of that which we term _resistance_, whatever it may be,
which impedes our continued effort, and impedes it variously as the
substances without are themselves various. Such is one order, then, of
the feelings commonly ascribed to the sense which we are at present
considering.
To proceed to the other supposed tangible qualities, before included in
our enumeration,--_figure_ is the boundary of extension, as _magnitude_
is that which it comprehends; and _divisibility_, if we consider the
apparent continuity of the parts which we divide, is only extension
under another name. If we except motion, therefore, which is not
permanent, but accidental,--and the knowledge of which is evidently
secondary to the knowledge which we acquire of our organs of sense,
before which the objects are said to move, and secondary in a much more
important sense, as resulting not from any direct immediate organic
state of one particular moment, but from a comparison of sensations
past and present,--all the information, which we are supposed to
receive primarily and directly from touch, relates to modifications of
_resistance_ and _extension_.
Though it is to the sense of _touch_, however, that the origin of the
knowledge of these is generally ascribed, I am inclined to think,
in opposition to this opinion, that in both cases, the reference is
wrongly made,--that if we had the sense of touch only, we should not
be sensible of resistance, nor, I conceive, even of extension,--and
that we seem to perceive the varieties of extension and resistance
immediately by touch only, because the simple original tactual feeling
has become representative of these, in the same manner, and for
the same reason, as we seem to perceive the varieties of distance
immediately by the eye. The sense of touch has unquestionably, like all
our other senses, its own peculiar feelings, though, for the simple
original feelings, attached to the affections of this most extensive
of organs, we have unfortunately no name, but that which is applied in
popular, and even in philosophic language, to all the affections of the
mind. Our joy or grief, hope or fear, love or hate, I before remarked,
we term _feelings_, as readily and frequently, as we use this term to
express our sensations of _touch_; and that, which, however restricted
in its original meaning, is now the common name of our mental
affections of every class, has, by this extension, unfortunately,
become a very unfit one, for distinguishing a limited order of those
affections.
Whatever be the term, which we may use, however, there _is_, and _must_
be, a sensation peculiar to touch, without regard to the extent or
quantity of the surface impressed,--as there is, in colour, a sensation
peculiar to vision, without regard to the extent of the portion of the
_retina_ on which the light may have fallen. Every physical point of
our organ of touch, when existing in a certain state, is capable of
inducing in the mind a peculiar feeling, though no other physical point
of the organ were affected,--as every physical point of the _retina_,
though but a single ray of light were admitted to the eye, is capable
of inducing in the mind a peculiar affection of vision; and when many
such physical points are affected together, by some impressing surface,
the form of which we think that we discover immediately by touch, it
is from experience only that we can learn the vicinity of the physical
points of our own tactual surface thus impressed, and consequently the
continued extension of the object which impresses them. Before we have
so much knowledge of external things, as to know even that we have any
bodily organs whatever,--and it is of this state of absolute ignorance
alone that we must think, as often as we speculate on the information
which our senses separately afford,--when we know as little of our
bodily frame, as of that material universe, of which we know nothing,
we cannot, by the very terms of this supposition, know that different
points of our organ of touch are affected in a certain manner,--that
these points are contiguous to each other--and that the mass affecting
these contiguous points must consequently itself be composed of points,
that are, in like manner, contiguous. We know nothing of our organs--we
know nothing of any external masses--but a certain feeling is excited
in our mind; and it is this simple feeling alone, whatever it may be,
which constitutes the direct elementary sensation of touch, though this
simple elementary sensation, like many other sensations, may afterwards
be so blended with other feelings, as to become significant of them,
and even to seem to involve them, as if originally and necessarily
coexisting.
It is impossible for us at present, indeed, to have a body impressed
on us, without the immediate notion of something external and
extended,--as it is impossible for one, whose sight is perfect, to
open his eyes, in the light of day, without perceiving, as it were
immediately, the long line of variegated landscape, in the scenery
before him:--the one impossibility is exactly equal to the other; yet
we know, in the case of vision, that all which we immediately perceive,
at the very moment, when our eyes seem to comprehend the worlds of half
infinity, in the hemisphere on Which we gaze, is a small expanse of
light,--if even, which I greatly doubt, there truly be, in our original
perceptions of this sense, so much of extension, as is implied in the
smallest possible expanse. In _touch_, in like manner, I conceive,
that the immediate sensation, though, like colour, it may now seem
inseparable from _extension_ and _outness_,--if, on the authority
of Berkeley, I may venture to use that barbarous but expressive
term,--was, like colour, originally distinct from them,--that, by the
mere original sensations of this organ, in short, we could as little
know the existence of an impressing body, as, by the mere original
sensations of vision, we could learn that such a body existed at the
extremity of the room in which we sit.
In defining sensation, when we began our inquiry into its nature,
I stated it to be that affection of the mind, which is immediately
subsequent to the affection of certain organs, induced by the action
of external bodies; and I admitted, that, in this definition two
assumptions were made,--the existence of foreign changeable external
bodies, as separate from the mind,--and the existence of organs, also
separate from the mind, and in relation to it truly external, like
other bodies, but forming a permanent part of our corporeal frame, and
capable of being affected, in a certain manner, by the other bodies,
of which the existence was assumed. As far as our analytical inquiry
has yet proceeded, these assumptions are assumptions still. We have not
been able to detect, in the sensations considered by us, more than in
any of our internal pleasures or pains, any circumstances that seem to
be indicative of a material world without.
Our analytical inquiry itself, however, even in attempting to trace
the circumstances, in which the belief originates, must proceed on
that very belief. Accordingly, in examining our senses of smell,
taste, and hearing, I uniformly took for granted the existence of
odoriferous, sapid, and vibrating bodies, and considered merely,
whether the sensations, excited by these, were, of themselves, capable
of communicating to us any knowledge of the external and independent
existence of the bodies which excited them.
In the present stage of our inquiry, I must, in like manner, take
for granted the existence of bodies, which act, by their contiguity
or pressure, on our organ of _touch_, as the odoriferous or sapid
particles, act on our nerves of smell and taste--not that I assume
this belief, as existing in the mind whose intellectual acquisitions
are the subject of inquiry,--for, in that case, the inquiry itself
would be superfluous. I assume it, merely as existing in the mind
of us the inquirers,--and only, because it is impossible, without
such an assumption to make the suppositions that are necessary for
the inquiry. All our language is at present adapted to a system of
external things. There is no direct vocabulary of scepticism; and even
the most cautious and philosophic inquirer, therefore, must often be
obliged to express his doubt, or his dissent, in language that implies
affirmation. In the present case, when we attempt to analyse our
sensations, it is impossible to speak of the circumstances in which the
infant is placed, or, I may say even, to speak of the infant himself,
without that assumption which we have been obliged to make. The real
existence of an external universe, and the belief of that existence,
are, however, in themselves, perfectly separate and distinct; and it is
not the existence of an external world, which we are now endeavouring
to establish as an object of belief. We are only endeavouring, in
our analysis of the sensations afforded by our different organs, to
ascertain in what circumstance the belief arises. There might be a
world of suns and planets, though there were no human being, whose
mind could be affected with belief of it; and even the most zealous
defenders of the reality of external nature must admit, that, though
no created thing but ourselves were in existence, our mind might still
have been so constituted, as to have the very series of feelings, which
form at present its successive phenomena, and which are ascribed in no
small number to the action of external things.
Are the _primary_ sensations derived from the organ of touch, then, of
such a kind as to afford us that knowledge, which they are supposed to
give of things without?
Let us imagine a being, endowed with the sense of _touch_, and with
every other sense and faculty of our mind, but _not_ with any previous
knowledge of his own corporeal frame, or of other things external,--and
let us suppose a small body, of any shape, to be pressed, for the first
time, on his open hand. Whatever feelings mere touch can give, directly
of itself, would of course be the same in this case, as _now_, when our
knowledge is increased, and complicated, from many other sources.
Let the body, thus impressed, be supposed to be a small _cube_, of
the same temperature with the hand itself, that all consideration of
heat or cold may be excluded, and the feeling produced be as simple as
possible.
What, then, may we suppose the consequent feeling to be?
It will, I conceive, be a simple feeling of the kind of which I have
already spoken, as capable of arising from the affection of a single
point of our organ of touch,--a feeling that varies indeed with the
quantity of pressure, as the sensation of fragrance varies with the
number of the odorous particles, but involves as little the notion of
extension, as that notion is involved in the mere fragrance of a violet
or a rose. The connection of this original tactual feeling, however,
with that of extension, is, _now_, so indissoluble, as, indeed, it
could not fail to become, in the circumstance in which it has uniformly
arisen, that it is almost impossible to conceive it as separate. We
may perhaps, however, make a near approach to the conception of it,
by using the gentle gradual pressure of a small pointed body, which,
in the various slight feelings, excited by it,--before it penetrate
the cuticle, or cause any considerable pain,--may represent, in some
measure, the simple and immediate effect, which pressure in any case
produces,--exclusively of the associate feelings which it indirectly
suggests.
Such of you, as have the curiosity to try the experiment, with any
small bodies, not absolutely pointed,--such as the head of a pin,
or any body of similar dimensions,--will be astonished to feel, how
very slightly, if at all, the notion of _extension_ or _figure_ is
involved in the feeling, even after all the intimate associations of
our experience;--certainly far less than the notion of longitudinal
distance seems to us to be involved in the immediate affections of our
sense of sight. It is an experiment, therefore, which I must request
you not to neglect to make.
But the pressure of such a large body, as the cube, which we have
supposed to be pressed against our organ of touch, _now_ awakens very
different feelings. We perceive, as it were immediately, _form_ and
_hardness_. May not, then, the knowledge of resistance and extension,
and consequently the belief of the essential qualities of matter,--be
originally communicated by the affections of this organ?
The feeling of _resistance_,--to begin with this,--is, I conceive, to
be ascribed, not to our organ of touch, but to our muscular frame,
to which I have already more than once directed your attention,
as forming a distinct organ of sense; the affections of which,
particularly as existing in combination with other feelings, and
modifying our judgments concerning these, (as in the case of distant
vision, for example,) are not less important than those of our other
sensitive organs. The sensations of this class, are, indeed, in common
circumstances, so obscure, as to be scarcely heeded or remembered by
us; but there is probably no contraction, even of a single muscle,
which is not attended with some faint degree of sensation, that
distinguishes it from the contractions of other muscles, or from other
degrees of contraction of the same muscle. I must not be understood,
however, as meaning that we are able, in this manner, by a sort of
instinctive anatomy, to perceive and number our own muscles, and when
many of them are acting together, as they usually do, to distinguish
_each_ from _each_; for, till we study the internal structure of our
frame, we scarcely know more, than that we have limbs which move at
our will, and we are altogether ignorant of the complicated machinery
which is subservient to the volition. But each motion of the visible
limb, whether produced by one or more of the invisible muscles, is
accompanied with a certain feeling, that may be _complex_, indeed, as
arising from various muscles, but which is considered by the mind as
_one_; and it is this particular feeling, accompanying the particular
visible motion,--whether the feeling and the invisible parts contracted
be truly simple or compound,--which we distinguish from every other
feeling accompanying every other quantity of contraction. It is as if a
man, born blind, were to walk, for the first time, in a flower garden.
He would distinguish the fragrance of one parterre from the fragrance
of another, though he might be altogether ignorant of the separate
odours united in each; and might even consider as one simple perfume,
what was, in truth, the mingled product of a thousand.
Obscure as our muscular sensations are in common circumstances, there
are other circumstances,--which I pointed out to you in treating before
of this subject,--in which they make themselves abundantly manifest.
I need not refer to the diseased state of the muscles, in which they
become painfully sensible; and I will admit, that the reference to such
a morbid state, in which the structure may be supposed to be altered
by the disease, would perhaps scarcely be a fair one. It is sufficient
to refer to phenomena of which every one must have been conscious
innumerable times, and which imply no disease nor lasting difference
of state. What is the feeling of fatigue, for example, but a muscular
feeling? that is to say, a feeling of which our muscles are as truly
the organ, as our eye or ear is the organ of sight or hearing. When a
limb has been long exercised, without sufficient intervals of rest,
the repetition of the contraction of its muscles is accompanied, not
with a slight and obscure sensation, but with one which amounts, if it
be gradually increased, to severe pain, and which before it arrives at
this, has passed progressively through various stages of uneasiness.
Even when there has been no previous fatigue, we cannot make a single
powerful effort at any time, without being sensible of the muscular
feeling connected with this effort. Of the pleasure which attends more
moderate exercise, every one must have been conscious in himself, even
in his years of maturity, when he seldom has recourse to it for the
pleasure alone; and must remember, still more the happiness which it
afforded him in other years, when happiness was of less costly and
laborious production than at present. By that admirable provision,
with which nature accommodates the blessings which she gives, to the
wants that stand in need of them, she has, in that early period,--when
the pleasure of mental freedom, and the ambitions of busy life, are
necessarily excluded,--made ample amends to the little slave of
affection, in that disposition to spontaneous pleasure, which renders
it almost an effort to be sad, as if existence itself were delight;
giving him a fund of independent happiness in the very air which
she has poured around him, and the ready limbs which move through
it, almost without his bidding. In that beautiful passage, in which
Goldsmith describes the sounds that come in one mingled murmur from
the village, who does not feel the force of the happiness which is
comprised in the single line, that speaks of
“The playful children, just let loose from school?”[84]
It is not the mere freedom from the intellectual task of which we
think; it is much more, that burst of animal pleasure, which is felt in
every limb, when the long constraint that has repressed it is removed,
and the whole frame is given once more to all the freedom of nature.
It is by the pleasure of exertion, and the pain of inexertion, that
we are roused from that indolence, into which, with great injury to
society, that requires our contribution of active aid, we otherwise
might sink;--as we are roused, in like manner, by the pleasure of food,
and the pain of hunger, to take the aliment that is necessary for our
individual sustenance; and though the mere aliment is, indeed, more
important for life, it is not more important for happiness than that
pleasure of activity which calls and forces us from our slothful repose.
“Thee, too, My Paridel,--I saw thee there,
Stretch'd on the rack of a too easy chair.”
With the same happy provision with which she has considered the young
of our own species, Nature has, in the other animals, whose sources of
general pleasure are still more limited than in the child, converted
their muscular frame into an organ of delight. It is not in search of
richer pasture that the horse gallops over his field, or the goat leaps
from rock to rock; it is for the luxury of the exercise itself. “If the
shell-fish on the shore,” says Dr Ferguson, “perform no visible action
but that of opening and closing his shell, to receive the brine that
accommodates, or to exclude the foul matter that annoys him, there are
other animals that, in the opposite extreme, are _active_; and for whom
Nature seems to administer the means of supply, merely as a restorative
of that strength which they are so freely to waste in the seemingly
sportive or violent exercises to which they are disposed.”[85]
“The bounding fawn, that darts across the glade,
When none pursues, through mere delight of heart,
And spirits buoyant, with excess of glee;
The horse as wanton, and almost as fleet,
That skims the spacious meadow at full speed,
Then stops, and snorts, and, throwing high his heels,
Starts to the voluntary race again;
The very kine, that gambol at high noon,--
The total herd,--receiving first from one,
That leads the dance, a summons to be gay;
Though wild their strange vagaries, and uncouth
Their efforts, yet resolved, with one consent,
To give such act and utterance as they may
To ecstacy, too big to be suppress'd.”[86]
It is this appearance of _happy life_ which spreads a charm over every
little group, with which Nature animates her scenery; and he who can
look without interest on the young lamb, as it frolics around the bush,
may gaze, indeed, on the magnificent landscape as it opens before
him,--but it will be with an eye which looks languidly, and in vain,
for pleasure which it cannot find.