_The Intellectual Faculties derived from the Faculty of Feeling_.
To convince ourselves that the faculties called _intellectual_, are
only certain modes of existence, or determinate manners of acting,
which result from the peculiar organization of the body, we have only
to analyze them; we shall then see that all the operations which are
attributed to the soul, are nothing more than certain modifications
of the body; of which a substance that is without extent, that has no
parts, that is immaterial, is not susceptible.
The first faculty we behold in the living man, and that from which all
his others flow, is _feeling_: however inexplicable this faculty may
appear, on a first view, if it be examined closely, it will be found
to be a consequence of the essence, or a result of the properties
of organized beings; the same as _gravity, magnetism, elasticity,
electricity_, &c. result from the essence or nature of some others. We
shall also find these last phenomena are not less inexplicable than that
of feeling. Nevertheless, if we wish to define to ourselves a clear and
precise idea of it, we shall find that feeling is a particular manner of
being moved--a mode of receiving an impulse peculiar to certain organs
of animated bodies, which is occasioned by the presence of a material
object that acts upon these organs, and transmit the impulse or shock to
the brain.
Man only feels by the aid of nerves dispersed through his body; which is
itself, to speak correctly, nothing more than a great nerve; or may
be said to resemble a large tree, of which the branches experience the
action of the root, communicated through the trunk. In man the nerves
unite and lose themselves in the brain; that intestine is the true seat
of feeling: like the spider in the centre of his web, it is quickly
warned of all the changes that happen to the body, even at the
extremities to which it sends its filaments and branches. Experience
enables us to ascertain, that man ceases to feel in those parts of his
body of which the communication with the brain is intercepted; he feels
very little, or not at all, whenever this organ is itself deranged or
affected in too lively a manner. A proof of this is afforded in the
transactions of the Royal Academy of Sciences at Paris: they inform us
of a man who had his scull taken off, in the room of which his brain was
recovered with skin; in proportion as a pressure was made by the hand on
his brain, the man fell into a kind of insensibility, which deprived
him of all feeling. BARTOLIN says, the brain of a man is twice as big as
that of an ox. This observation had been already made by ARISTOTLE.
In the dead body of an idiot dissected by WILLIS, the brain was found
smaller than ordinary: he says the greatest difference he found between
the parts of the body of this idiot, and those of wiser men, was, that
the plexus of the intercostal nerves, which is the mediator between the
brain and the heart, was extremely small, accompanied by a less number
of nerves than usual. According to WILLIS, the ape is, of all animals,
that which has the largest brain, relatively to his size: he is also,
after man, that which has the most intelligence: this is further
confirmed, by the name he bears in the soil, to which he is indigenous,
which is _ourang outang_, or the man beast. There is, therefore, every
reason to believe that it is entirely in the brain, that consists the
difference, that is found not only between man and beasts, but also
between the man of wit, and the fool: between the thinking man, and he
who is ignorant; between the man of sound understanding, and the madman:
a multitude of experience, serves to prove, that those persons who are
most accustomed to use their intellectual faculties, have their brain
more extended than others: the same has been remarked of watermen, that
they have arms much longer than other men.
However this may be, the sensibility of the brain, and all its parts, is
a fact: if it be asked, whence comes this property? We shall reply,
it is the result of an arrangement, of a combination, peculiar to the
animal: it is thus that milk, bread, wine, change themselves in the
substance of man, who is a sensible being: this insensible matter
becomes sensible, in combining itself with a sensible whole. Some
philosophers think that sensibility is a universal quality of matter:
in this case, it would be useless to seek from whence this property is
derived, as we know it by its effects. If this hypothesis be admitted,
in like manner as two kinds of motion are distinguished in Nature, the
one called _live_ force, the other _dead_, or _inert_ force, two sorts
of sensibility will be distinguished, the one active or alive, the other
inert or dead. Then to animalize a substance, is only to destroy
the obstacles that prevent its being active or sensible. In fact,
sensibility is either a quality which communicates itself like motion,
and which is acquired by combination; or this sensibility is a property
inherent in all matter: in both, or either case, an unextended being,
without parts, such as the human soul is said to be, can neither be the
cause of it nor submitted to its operation; but we may fairly conclude,
that all the parts of Nature enjoy the capability to arrive at
animation; the obstacle is only in the state, not in the quality. Life
is the perfection of Nature: she has no parts which do not tend to
it--which do not attain it by the same means. Life in an insect, a dog,
a man, has no other difference, than that this act is more perfect,
relatively to ourselves in proportion to the structure of the organs:
if, therefore, it be asked, what is requisite to animate a body? we
reply, it needs no foreign aid; it is sufficient that the power of
Nature be joined to its organization.
The conformation, the arrangement, the texture, the delicacy of the
organs, as well exterior as interior, which compose men and animals,
render their parts extremely mobile, or make their machine susceptible
of being moved with great facility. In a body, which is only a heap
of fibres, a mass of nerves, contiguous one to the other, united in a
common center, always ready to act; in a whole, composed of fluids and
solids, of which the parts are in equilibrium, the smallest touching
each other, are active in their motion, communicating reciprocally,
alternately and in succession, the impression, oscillations, and shocks
they receive; in such a composition, it is not surprising that the
slightest impulse propagates itself with celerity; that the shocks
excited in its remotest parts, make themselves quickly felt in the
brain, whose delicate texture renders it susceptible of being itself
very easily modified. Air, fire, water, agents the most inconstant,
possessing the most rapid motion, circulate continually in the fibres,
incessantly penetrate the nerves: without doubt these contribute to that
incredible celerity with which the brain is acquainted with what passes
at the extremities of the body.
Notwithstanding the great mobility with which man's organization renders
him susceptible, although exterior as well as interior causes are
continually acting upon him, he does not always feel in a distinct, in
a decided manner, the impulse given to his senses: indeed, he does not
feel it, until it has produced some change, or given some shock to his
brain. Thus, although completely environed by air, he does not feel its
action, until it is so modified, as to strike with a sufficient degree
of force on his organs; to penetrate his skin, through which his brain
is warned of its presence. Thus, during a profound and tranquil sleep,
undisturbed by any dream, man ceases to feel. In short, notwithstanding
the continued motion that agitates his frame, man does not appear to
feel, when this motion acts in a convenient order; he does not perceive
a state of health, but he discovers a state of grief or sickness;
because, in the first, his brain does not receive too lively an impulse,
whilst in the others, his nerves are contracted, shocked, and agitated,
with violent, with disorderly motion: these communicating with his
brain, give notice that some cause acts strongly upon them--impels
them in a manner that bears no analogy with their natural habit: this
constitutes, in him, that peculiar mode of existing which he calls
_grief_.
On the other hand, it sometimes happens that exterior objects produce
very considerable changes on his body, without his perceiving them at
the moment. Often, in the heat of battle, the soldier perceives not
that he is dangerously wounded, because, at the time, the rapidity, the
multiplicity of impetuous motion that assails his brain, does not
permit him to distinguish the particular change a part of his body has
undergone by the wound. In short, when a great number of causes are
simultaneously acting on him with too much vivacity, he sinks under
their accumulated pressure,--he swoons--he loses his senses--he is
deprived of feeling.
In general, feeling only obtains, when the brain can distinguish
distinctly, the impressions made on the organs with which it has
communication; it is the distinct shock, the decided modification man
undergoes, that constitutes _conscience_. Doctor Clarke, says to this
effect: "Conscience is the act of reflecting, by means of which I know
that I think, and that my thoughts, or my actions belong to me, and
not to another." From this it will appear, that _feeling_ is a mode of
being, a marked change, produced on our brain, occasioned by the impulse
communicated to our organs, whether by interior or exterior agents, by
which it is modified either in a durable or transient manner: it is
not always requisite that man's organs should be moved by an exterior
object, to enable him to feel that he should be conscious of the changes
effected in him: he can feel them within himself by means of an interior
impulse; his brain is then modified, or rather he renews within himself
the anterior modifications. We are not to be astonished that the brain
should be necessarily warned of the shocks, of the impediments, of the
changes that may happen to so complicated a machine as the human body,
in which, notwithstanding all the parts are contiguous to the brain,
and concentrate themselves in this brain, and are by their essence in a
continual state of action and re-action.
When a man experiences the pains of the gout, he is conscious of them;
in other words, he feels interiorly, that it has produced very marked,
very distinct changes in him, without his perceiving, that he has
received an impulse from any exterior cause; nevertheless, if he will
recur to the true source of these changes, he will find that they have
been wholly produced by exterior agents: they have been the consequence,
either of his temperament; of the organization received from his
parents; of the aliments with which his frame has been nourished;
besides a thousand trivial, inappreciable causes, which congregating
themselves by degrees produce in him the gouty humour; the effect of
which is to make him feel in an acute and very lively manner. The pain
of the gout engenders in his brain an idea, so modifies it that it
acquires the faculty of representing to itself, of reiterating as it
were, this pain when even he shall be no longer tormented with the gout:
his brain, by a series of motion interiorly excited, is again placed
in a state analogous to that in which it was when he really experienced
this pain: but if he had never felt it, he would never have been in a
capacity to form to himself any just idea of its excruciating torments.
The visible organs of man's body, by the intervention of which his brain
is modified, take the name of _senses_. The various modifications which
his brain receives by the aid of these senses, assumes a variety of
names. _Sensation_, _perception_, and _idea_, are terms that designate
nothing more than the changes produced in this interior organ, in
consequence of impressions made on the exterior organs by bodies
acting on them: these changes considered by themselves, are called
_sensations_; they adopt the term _perception_ when the brain is warned
of their presence; _ideas_ is that state of them in which the brain is
able to ascribe them to the objects by which they have been produced.
Every _sensation_, then, is nothing more than the shock given to the
organs, every _perception_ is this shock propagated to the brain;
every _idea_ is the image of the object to which the sensation and the
perception is to be ascribed. From whence it will be seen, that if the
senses be not moved, there can neither be sensations, perceptions, nor
ideas: this will be proved to those, who can yet permit themselves to
doubt so demonstrable and striking a truth.
It is the extreme mobility of which man is capable, owing to his
peculiar organization, that distinguishes him from other beings that are
called insensible or inanimate; the different degrees of this mobility,
of which the individuals of his species are susceptible, discriminate
them from each other; make that incredible variety, that infinity of
difference which is to be found, as well in their corporeal faculties,
as in those which are mental or intellectual. From this mobility,
more or less remarkable in each human being, results wit, sensibility,
imagination, taste, &c.: for the present, however, let us follow the
operation of the senses; let us examine in what manner they are
acted upon, and are modified by exterior objects:--we will afterwards
scrutinize the re-action of the interior organ or brain.
The eyes are very delicate, very movable organs, by means of which the
sensation of light or colour is experienced: these give to the brain
a distinct perception, in consequence of which, man forms an idea,
generated by the action of luminous or coloured bodies: as soon as the
eyelids are opened, the retina is affected in a peculiar manner; the
fluid, the fibres, the nerves, of which they are composed, are excited
by shocks which they communicate to the brain; to which they delineate
the images of the bodies from which they have received the impulse; by
this means, an idea is acquired of the colour, the size, the form, the
distance of these bodies: it is thus that may be explained the mechanism
of _sight_.
The mobility and the elasticity of which the skin is rendered
susceptible, by the fibres and nerves which form its texture, accounts
for the rapidity with which this envelope to the human body is affected
when applied to any other body; by their agency, the brain has notice of
its presence, of its extent, of its roughness, of its smoothness, of its
surface, of its pressure of its ponderosity, &c. Qualities from which
the brain derives distinct perceptions, which breed in it a diversity of
ideas; it is this that constitutes the _touch_ or _feeling_.
The delicacy of the membrane by which the interior of the nostrils is
covered, renders them easily susceptible of irritation, even by the
invisible and impalpable corpuscles that emanate from odorous bodies:
by these means sensations are excited, the brain has perceptions, and
generates ideas: it is this that forms the sense of _smelling_.
The mouth, filled with nervous, sensible, movable, irritable glands,
saturated with juices suitable to the dissolution of saline substances,
is affected in a very lively manner by the aliments which pass through
it for the nourishment of the body; these glands transmit to the brain
the impressions received: perceptions are of consequence; ideas follow:
it is from this mechanism that results _taste_.
The ear, whose conformation fits it to receive the various impulses
of air, diversely modified, communicates to the brain the shocks or
sensations; these breed the perception of sound, and generate the idea
of sonorous bodies: it is this that constitutes _hearing_.
Such are the only means by which man receives sensations, perceptions,
and ideas. These successive modifications of his brain are effects
produced by objects that give impulse to his senses; they become
themselves causes, producing in his soul new modifications, which are
denominated _thought, reflection, memory, imagination, judgment, will,
action_; the basis, however, of all these is _sensation_.
To form a precise notion of _thought_, it will be requisite to examine,
step by step, what passes in man during the presence of any object
whatever. Suppose for a moment this object to be a peach: this fruit
makes, at the first view, two different impressions on his eyes; that
is to say, it produces two modifications, which are transmitted to the
brain, which on this occasion experiences two new perceptions, or has
two new ideas or modes of existence, designated by the terms _colour_
and _rotundity_; in consequence, he has an idea of a body possessing
roundness and colour: if he places his hand on this fruit, the organ
of feeling having been set in action, his hand experiences three new
impressions, which are called _softness, coolness, weight_, from whence
result three new perceptions in the brain, he has consequently three
new ideas: if he approximates this peach to his nose, the organ of
_smelling_ receives an impulse, which, communicated to the brain, a new
perception arises, by which he acquires a new idea, called _odour_: if
he carries this fruit to his mouth, the organ of taste becomes affected
in a very lively manner: this impulse communicated to the brain, is
followed by a perception that generates in him the idea of _flavour_. In
re-uniting all these impressions, or these various modifications of his
organs, which it have been consequently transmitted to his brain; that
is to say, in combining the different sensations, perceptions, and
ideas, that result from the impulse he has received, he has an idea of
a whole, which he designates by the name of a peach, with which he can
then occupy his thoughts.
From this it is sufficiently proved that thought has a commencement, a
duration, an end; or rather a generation, a succession, a dissolution,
like all the other modifications of matter; like them, thought is
excited, is determined, is increased, is divided, is compounded, is
simplified, &c. If, therefore, the soul, or the principle that thinks,
be indivisible; how does it happen, that this soul has the faculty of
memory, or of forgetfulness; is capacitated to think successively, to
divide, to abstract, to combine, to extend its ideas, to retain them,
or to lose them? How can it cease to think? If forms appear divisible in
matter, it is only in considering them by abstraction, after the method,
of geometricians; but this divisibility of form exists not in Nature, in
which there is neither a point, an atom, nor form perfectly regular;
it must therefore be concluded, that the forms of matter are not less
indivisible than thought.
What has been said is sufficient to show the generation of sensations,
of perceptions, of ideas, with their association, or connection in the
brain: it will be seen that these various modifications are nothing more
than the consequence of successive impulses, which the exterior organs
transmit to the interior organ, which enjoys the faculty of thought,
that is to say, to feel in itself the different modifications it has
received, or to perceive the various ideas which it has generated; to
combine them, to separate them, to extend them, to abridge them, to
compare them, to renew them, &c. From whence it will be seen, that
thought is nothing more than the perception of certain modifications,
which the brain either gives to itself, or has received from exterior
objects.
Indeed, not only the interior organ perceives the modifications it
receives from without, but again it has the faculty of modifying itself;
of considering the changes which take place in it, the motion by which
it is agitated in its peculiar operations, from which it imbibes new
perceptions and new ideas. It is the exercise of this power to fall back
upon itself, that is called _reflection_.
From this it will appear, that for man to think and to reflect, is to
feel, or perceive within himself the impressions, the sensations, the
ideas, which have been furnished to his brain by those objects which
give impulse to his senses, with the various changes which his brain
produced on itself in consequence.
_Memory_ is the faculty which the brain has of renewing in itself the
modifications it has received, or rather, to restore itself to a state
similar to that in which it has been placed by the sensations, the
perceptions, the ideas, produced by exterior objects, in the exact order
it received them, without any new action on the part of these objects,
or even when these objects are absent; the brain perceives that these
modifications assimilate with those it formerly experienced in the
presence of the objects to which it relates, or attributes them. Memory
is faithful, when these modifications are precisely the same; it
is treacherous, when they differ from those which the organs have
exteriorly experienced.
_Imagination_ in man is only the faculty which the brain has of
modifying itself, or of forming to itself new perceptions, upon the
model of those which it has anteriorly received through the action of
exterior objects on the senses. The brain, then, does nothing more than
combine ideas which it has already formed, which it recalls to itself,
from which it forms a whole, or a collection of modifications, which
it has not received, which exists no-where but in itself, although the
individual ideas, or the parts of which this ideal whole is composed,
have been previously communicated to it, in consequence of the impulse
given to the senses by exterior objects: it is thus man forms to himself
the idea of _centaurs_, or a being composed of a man and a horse, of
_hyppogriffs_, or a being composed of a horse with wings and a griffin,
besides a thousand other objects, equally ridiculous. By memory, the
brain renews in itself the sensations, the perceptions, and the ideas
which it has received or generated; represents to itself the objects
which have actually moved its organs. By imagination it combines them
variously: forms objects in their place which have not moved its organs,
although it is perfectly acquainted with the elements or ideas of which
it composes them. It is thus that man, by combining a great number
of ideas borrowed from himself, such as justice, wisdom, goodness,
intelligence, &c. by the aid of imagination, has formed various ideal
beings, or imaginary wholes, which he has called JUPITER, JUNO, BRAMAH,
SATURN, &c.
_Judgment_ is the faculty which the brain possesses of comparing with
each other the modifications it receives, the ideas it engenders, or
which it has the power of awakening within itself, to the end that it
may discover their relations, or their effects.
_Will_ is a modification of the brain, by which it is disposed to
action, that is to say, to give such an impulse to the organs of the
body, as can induce to act in a manner, that will procure for itself
what is requisite to modify it in a mode analogous to its own existence,
or to enable it to avoid that by which it can be injured. To _will_ is
to be disposed to _action_. The exterior objects, or the interior ideas,
which give birth to this disposition are called _motives_, because they
are the springs or movements which determine it to act, that is to say,
which give play to the organs of the body. Thus, _voluntary actions_
are the motion of the body, determined by the modification of the
brain. Fruit hanging on a tree, through the agency of the visual organs,
modifies the brain in such a manner as to dispose the arm to stretch
itself forth to cull it; again, it modifies it in another manner, by
which it excites the hand to carry it to the mouth.
All the modifications which the interior organ or the brain receives,
all the sensations, all the perceptions, all the ideas that are
generated by the objects which give impulse to the senses, or which
it renews within itself by its own peculiar faculties, are either
favourable or prejudicial to man's mode of existence, whether that be
transitory or habitual: they dispose the interior organ to action, which
it exercises by reason of its own peculiar energy: this action is not,
however, the same in all the individuals of the human species, depending
much on their respective temperaments. From hence the PASSIONS have
their birth: these are more or less violent; they are, however, nothing
more than the motion of the will, determined by the objects which give
it activity; consequently composed of the analogy or of the discordance
which is found between these objects, man's peculiar mode of existence,
and the force of his temperament. From this it results, that the
passions are modes of existence or modifications of the brain; which
either attract or repel those objects by which man is surrounded; that
consequently they are submitted in their action to the physical laws of
attraction and repulsion.
The faculty of perceiving or of being modified, as well by itself as
exterior objects which the brain enjoys is sometimes designated by the
term _understanding_. To the assemblage of the various faculties
of which this interior organ is susceptible, is applied the name of
_intelligence_. To a determined mode in which the brain exercises the
faculties peculiar to itself, is given the appellation of _reason_. The
dispositions or the modifications of the brain, some of them constant,
others transitory, which give impulse to the beings of the human
species, causing them to act, are styled _wit, wisdom, goodness,
prudence, virtue, &c_.
In short, as there will be an opportunity presently to prove, all
the intellectual faculties--that is to say, all the modes of action
attributed to the soul, may be reduced to the modifications, to the
qualities, to the modes of existence, to the changes produced by the
motion of the brain; which is visibly in man the seat of feeling, the
principle of all his actions. These modifications are to be attributed
to the objects that strike on his senses; of which the impression is
transmitted to the brain, or rather to the ideas, which the perceptions
caused by the action of these objects on his senses have there
generated, and which it has the faculty to re-produce. This brain moves
itself in its turn, re-acts upon itself, gives play to the organs, which
concentrate themselves in it, or which are rather nothing more than an
extension of its own peculiar substance. It is thus the concealed motion
of the interior organ, renders itself sensible by outward and visible
signs. The brain, affected by a modification which is called FEAR,
diffuses a paleness over the countenance, excites a tremulous motion in
the limbs called trembling. The brain, affected by a sensation of GRIEF,
causes tears to flow from the eyes, even without being moved by any
exterior object; an idea which it retraces with great strength, suffices
to give it very little modifications, which visibly have an influence on
the whole frame.
In all this, nothing more is to be perceived than the same substance
which acts diversely on the various parts of the body. If it be objected
that this mechanism does not sufficiently explain the principles of the
motion or the faculties of the soul; we reply, that it is in the same
situation as all the other bodies of Nature, in which the most simple
motion, the most ordinary phenomena, the most common modes of action are
inexplicable mysteries, of which we shall never be able to fathom the
first principles. Indeed, how can we flatter ourselves we shall ever be
enabled to compass the true principle of that gravity by which a stone
falls? Are we acquainted with the mechanism which produces attraction in
some substances, repulsion in others? Are we in a condition to explain
the communication of motion from one body to another? But it may be
fairly asked,--Are the difficulties that occur, when attempting to
explain the manner in which the soul acts, removed by making it a
_spiritual being_, a substance of which we have not, nor cannot form one
idea, which consequently must bewilder all the notions we are capable
of forming to ourselves of this being? Let us then be contented to know
that the soul moves itself, modifies itself, in consequence of material
causes, which act upon it which give it activity: from whence the
conclusion may be said to flow consecutively, that all its operations,
all its faculties, prove that it is itself _material_.