ADDITIONAL NOTES. II.
THE FACULTIES OF THE SENSORIUM.
Next
the long nerves
unite their silver
train,
And
young
Sensation
permeates
the
brain. CANTO
I.
1.
250. |
I.
THE fibres,
which constitute
the muscles and organs
of sense, possess a
power
of contraction. The
circumstances
attending the exertion
of this power of contraction
constitute the laws
of
animal motion, as the
circumstances attending
the exertion of the
power
of attraction constitute
the laws of motion of
inanimate matter.
II.
The
spirit
of
animation
is
the
immediate
cause
of
the
contraction
of
animal
fibres,
it
resides
in
the
brain
and
nerves,
and
is
liable
to
general
or
partial
diminution
or
accumulation.
III.
The
stimulus
of
bodies
external
to
the
moving
organ
is
the
remote
cause
of
the
original
contractions
of
animal
fibres.
IV.
A
certain
quantity
of
stimulus
produces
irritation,
which
is
an
exertion
of
the
spirit
of
animation
exciting
the
fibres
into
contraction.
V.
A
certain
quantity
of
contraction
of
animal
fibres,
if
it
be
perceived
at
all,
produces
pleasure;
a
greater
or
less
quantity
of
contraction,
if
it
be
perceived
at
all,
produces
pain;
these
constitute
sensation.
VI.
A
certain
quantity
of
sensation
produces
desire
or
aversion;
these
constitute
volition.
VII.
All
animal
motions
which
have
occurred
at
the
same
time,
or
in
immediate
succession,
become
so
connected,
that
when
one
of
them
is
reproduced,
the
other
has
a
tendency
to
accompany
or
succeed
it.
When
fibrous
contractions
succeed
or
accompany
other
fibrous
contractions,
the
connexion
is
termed
association;
when
fibrous
contractions
succeed
sensorial
motions,
the
connexion
is
termed
causation;
when
fibrous
and
sensorial
motions
reciprocally
introduce
each
other,
it
is
termed
catenation
of
animal
motions.
VIII.
These
four
faculties
of
the
sensorium
during
their
inactive
state
are
termed
irritability,
sensibility,
voluntarity,
and
associability;
in
their
active
state
they
are
termed
as
above
irritation,
sensation,
volition,
association.
Irritation
is
an
exertion
or
change
of
some
extreme
part
of
the
sensorium
residing
in
the
muscles
or
organs
of
sense,
in
consequence
of
the
appulses
of
external
bodies.
Sensation
is
an
exertion
or
change
of
the
central
parts
of
the
sensorium,
or
of
the
whole
of
it,
beginning
at
some
of
those
extreme
parts
of
it,
which
reside
in
the
muscles
or
organs
of
sense.
Volition
is
an
exertion
or
change
of
the
central
parts
of
the
sensorium,
or
of
the
whole
of
it,
terminating
in
some
of
those
extreme
parts
of
it,
which
reside
in
the
muscles
or
organs
of
sense.
Association
is
an
exertion
or
change
of
some
extreme
part
of
the
sensorium
residing
in
the
muscles
or
organs
of
sense,
in
consequence
of
some
antecedent
or
attendant
fibrous
contractions;
see
Zoonomia,
Vol.
I.
The
word
sensorium
is
used
to
express
not
only
the
medullary
part
of
the
brain,
spinal
marrow,
nerves,
organs
of
sense
and
muscles,
but
also
at
the
same
time
that
living
principle,
or
spirit
of
animation,
which
resides
throughout
the
body,
without
being
cognizable
to
our
senses
except
by
its
effects.
|