Year: 1874

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PROPOSITIONS OF THE THEORY


The matters with which we shall such as to
require no extensive knowledge of anatomy. need
only premise that what call the nervous system 10
the higher animals consists OF central apparatus
composed OF the brain, which ia lodged In the SKULL anu
OF cord proceeding from it, which is termed the spina
marrow, and which Is lodged In the vertebra column Vi
spne and that then from these soft white masses-ior
such they are-there proceed cords which are termed
nerves. some of which nerves end In the musc'o'
while others end In the organs OF sonSaion,
The first proposition that you ma oennteiy auu
clearly stated by Descartes Is the view that the brain
the organ Of sensation, Of thought and OF emouoh-
using the word "organ" in this sense, that certain
changes which take place the matter OF the brain
ara the essential antecedens OF those states or con-
sciousness which term sensation, thought, and emo
ton II your friend disagrees with your opinion. runs
amuck against any Of your pet preudices, you say,
"Ah poor fellow he is little touched here" by which
you his brain is not doing its business prop
erly-that he is not thinking properly-thereby I'M
plying that his brain is way affected. 1t re-
maned down to the time Of Bicbat question
whether the passions were not located in
the abdominal vscers In the second place, Descartes
lays down the proposition that all the movements OF
the animal bodies affected by change of form Of


part of the matter Of their bodies, to which
he applies the general term Of MUSCLE That Is a
proposition which is placed beyond all doubt what
ever II move my arm. that movement is due to the
charge of this in front called the bceps muscle;
1t Is shortened till 1t becomes thicker. II move any OF
my limbs the reason is the same. AS now speak to
you different OF my voice due to the ex-
quisitey accurate adjustments and adjusted contrac
tions Of multitude OF such particles Of flesh; and
there is considerable and visible movement
OF .the animal body which is not, Descartes
says. resolvabe into these changes in the form Of
matter termed muscle. Bat Descartes went further,
and rHinaFu
OF things these changes in the form OF muscle In the


living body only under certain conditions; and
the essential condition OF the change was, says Des
cartes the motion OF the matter contained within the
nerves which from the central apparatus to the
muscle Descartes gave this moving material particu


lar name-the animal spirits. Nowadays.we should not
say that the animal spirits existed. but should say
that molecular change takes place In the and
that that molecular change is propagated at certain
velocity which has been measured from the central ap
paratus the muscle. Modern physiology has meas
ured the of the change to which have referred.


ACCORDANCE OF DEscARTEs's VIEWS WITH OUR OWN.


Next Descartes says that under ordinary circum.
stances, this change the contents of nerve, which
gives the contraction Of MUSCLE is produced by


change in the central nervous apparatus, as for
ample the BRAIN We at the present time exactly the
same thing Descartes said that the animal spirits were
stored up the brain and flowed out from the motor
nerve. We say that molecular change takes place in
the brain that Is propagated along the motor nerve
Further, Descartes stated that the sensory organs
which give rise TO feelings, gave rise to change
in tho sensory nerves, to flow of animal
spirits along those nerves. which flow pro-
pagated to the brain, II look at this candle before
the light falling the retina Of my eye gives rise to
affection OF the optic nerve which affection Descartes
described Cow OF the animal spirits to the brain;
but the fundamental idea is the same. In all our
tons of the operations of nerve building upon
Descartes's foundation. He says that when body
which is competent TO produce sensation touches the
sensorv organs, what happens is the production Of


mode OF motion Of the nerves. That mode OF
motion is propagated to the brain. That which
takes place in the brain is still nothing but q
mode of motion But in addition 10 this mode
OF motion there is. everybody find by expert
ment for himself something else which can in no way
DE compared to notion which is utterly unlike 1t, and
which Is that state OF consciousness which we call a
sensation. Descartes insists and again
this disparity between the agent which excites
the OF consciousness and the state OF conscious
ness itself He tells that sensations not
pictures OF external things, but that they are
symbols signs OF them and in doing that
he made one Of the greatest possible revOlu-
tons only in physiology but in philosophy. Till his
time the notion that visible bodies for example,
gave from themselves kind of film which entered the
eye to the BRAIN species nentionaIes as they
were called and thus the mind received an actual copy
or picture OF things which given off from 1t. In
laying dOwn that proposition upon what imagine 10 DC


perfectly irrefragble basis, Descartes laid the foun-
dation of that of philosophy which is termed ideal
sm which subsequently, expanded to its uttermos
by Berkeley and has taken all sorts of shapes since.


AUTOMATIC BRAIN-wORK-THEoRY OF MEMORY.


But Descartes noticed not only under certain
dtons an impulse made by the sensOry organ may give
rise to sensation but that under certain other cond
tions may rise 10 motion, and that this motou
may be effected without sensation and not only without
yolition but even contrary to it, know in no modern
treatise of and precise statement than this
OF what understand by the automatic action OF the
brain And what remarkable is that in speaking
OF these movements which arise by sensation being as
1t reflected from the central apparatus into mD
as for example, when ones finger is prcked and the
arm is suddenly drawn up, the motion OF the sensory
nerve travels the spine and Is again reflected down 70
the OF the armDescartes uses the very phrase
that we this present time employ Aud the last great
service to physiology Of the nervous system which
have 10 mention rendered by Descartes was this,
that he rst know sketched out the physical
theory Of memory What he tells you in substance Is
this that when a sensation takes place, the animal
spirits travel up the nerve pass to the appro
pirate part of the brain, and there. as 1t were, ind
their way through the OF the substance OF the
brain. And he says that when the particles OF the
brain have themselves been showed aside little by the
single passage OF the animal isplrts, that the
passage is made easier in the same direc-
ton for any subsequent flow OF animal
spirits aud that the repetition OF this action
makes it easier STILL until at length IL becomes very
easy for the animal spirits to move these particular
particles OF the bran the motion OF which gives rise to
the appropriate sensation, until at length the passage
is so easy that almost anything, especially an
associated flow which may be set going, allows the
animal spirits to flow into these already open pores
more easily they would flow In any other direc
ton aid in this way dow of the animal spirits
recalls the image-the impression made by former
sensory act That again. essentially in substance at
once with all present physical theories OF memory
ooa Descartas proceeded further than