按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！
to reside； which； whenever it is disposed in the same
particular way； conveys the same thing to the mind； although
meanwhile the other portions of the body may be differently
disposed； as is testified by innumerable experiments which it
is unnecessary here to recount。
I notice； also； that the nature of body is such that none
of its parts can be moved by another part a little way off
which cannot also be moved in the same way by each one of the
parts which are between the two； although this more remote
part does not act at all。 As； for example； in the cord ABCD
＇which is in tension＇ if we pull the last part D； the first
part A will not be moved in any way differently from what
would be the case if one of the intervening parts B or C were
pulled； and the last part D were to remain unmoved。 And in
the same way； when I feel pain in my foot； my knowledge of
physics teaches me that this sensation is municated by
means of nerves dispersed through the foot； which； being
extended like cords from there to the brain； when they are
contracted in the foot； at the same time contract the inmost
portions of the brain which is their extremity and place of
origin； and then excite a certain movement which nature has
established in order to cause the mind to be affected by a
sensation of pain represented as existing in the foot。 But
because these nerves must pass through the tibia； the thigh；
the loins； the back and the neck； in order to reach from the
leg to the brain； it may happen that although their
extremities which are in the foot are not affected； but only
certain ones of their intervening parts ＇which pass by the
loins or the neck＇； this action will excite the same movement
in the brain that might have been excited there by a hurt
received in the foot； in consequence of which the mind will
necessarily feel in the foot the same pain as if it had
received a hurt。 And the same holds good of all the other
perceptions of our senses。
I notice finally that since each of the movements which
are in the portion of the brain by which the mind is
immediately affected brings about one particular sensation
only； we cannot under the circumstances imagine anything more
likely than that this movement； amongst all the sensations
which it is capable of impressing on it； causes mind to be
affected by that one which is best fitted and most generally
useful for the conservation of the human body when it is in
health。 But experience makes us aware that all the feelings
with which nature inspires us are such as I have just spoken
of； and there is therefore nothing in them which does not give
testimony to the power and goodness of the God ＇who has
produced them28＇。 Thus； for example； when the nerves which
are in the feet are violently or more than usually moved；
their movement； passing through the medulla of the spine29 to
the inmost parts of the brain； gives a sign to the mind which
makes it feel somewhat； to wit； pain； as though in the foot；
by which the mind is excited to do its utmost to remove the
cause of the evil as dangerous and hurtful to the foot。 It is
true that God could have constituted the nature of man in such
a way that this same movement in the brain would have conveyed
something quite different to the mind； for example； it might
have produced consciousness of itself either in so far as it
is in the brain； or as it is in the foot； or as it is in some
other place between the foot and the brain； or it might
finally have produced consciousness of anything else
whatsoever； but none of all this would have contributed so
well to the conservation of the body。 Similarly； when we
desire to drink； a certain dryness of the throat is produced
which moves its nerves； and by their means the internal
portions of the brain； and this movement causes in the mind
the sensation of thirst； because in this case there is nothing
more useful to us than to bee aware that we have need to
drink for the conservation o our health； and the same holds
good in other instances。
From this it is quite clear that； notwithstanding the
supreme goodness of God； the nature of man； inasmuch as it is
posed of mind and body； cannot be otherwise than sometimes
a source of deception。 For if there is any cause which
excites； not in the foot but in some part of the nerves which
are extended between the foot and the brain； or even in the
brain itself； the same movement which usually is produced when
the foot is detrimentally affected； pain will be experienced
as though it were in the foot； and the sense will thus
naturally be deceived； for since the same movement in the
brain is capable of causing but one sensation in the mind； and
this sensation is much more frequently excited by a cause
which hurts the foot than by another existing in some other
quarter； it is reasonable that it should convey to the mind
pain in the foot rather than in any other part of the body。
And although the parchedness of the throat does not always
proceed； as it usually does； from the fact that drinking is
necessary for the health of the body； but sometimes es from
quite a different cause； as is the case with dropsical
patients； it is yet much better that it should mislead on this
occasion than if； on the other hand； it were always to deceive
us when the body is in good health； and so on in similar
cases。
And certainly this consideration is of great service to
me； not only in enabling me to recognise all the errors to
which my nature is subject； but also in enabling me to avoid
them or to correct them more easily。 for knowing that all my
senses more frequently indicate to me truth than falsehood
respecting the things which concern that which is beneficial
to the body； and being able almost always to avail myself of
many of them in order to examine one particular thing； and；
besides that； being able to make use of my memory in order to
connect the present with the past； and of my understanding
which already has discovered all the causes of my errors； I
ought no longer to fear that falsity may be found in matters
every day presented to me by my senses。 And I ought to set
aside all the