Six metaphysical meditations · René Descartes
A⸺B⸺C⸺D
I understand lastly, that seeing each single motion perform’d in that part of the _Brain_, which _immediately affects_ the _mind_, excites therein only one sort of _sense_, nothing could be contrived more conveniently in this case, than that, of all those _Senses_ which it can cause, it should cause that which _cheifly_, and most _frequently_ conduces to the _conservation_ of an _healthful Man_; And experience witnesses, that to this very _end_ all our _senses_ are given us by _Nature_; and therefore nothing can be found therein, which does not abundantly testifie the _Power_ and _Goodness_ of _God_. Thus for Example, when the Nerves of the Feet are violently and more than ordinarily moved, that motion of them being propagated through the _Medulla Spinalis_ of the Back to the inward parts of the Brain, there it signifies to the mind, that something or other is to be felt, and what is this but Pain, as if it were in the Foot, by which the Mind is excited to use its indeavours for removing the Cause, as being hurtful to the Foot. But the _Nature_ of _Man_ might have been so _order’d_ by _God_, that That same motion in the Brain should represent to the mind any other thing, _viz._ either it self as ’tis in the Brain, or it self as it is in the Foot, or in any of the other forementioned intermediate parts, or lastly any other thing whatsoever; but none of these would have so much conduced to the _Conservation_ of the _Body_. In the like manner when we want drink, from thence arises a certain _dryness_ in the _Throat_, which moves the Nerves thereof, and by their means the inward parts of the Brain, and this motion _affects_ the _mind_ with the _sense_ of _thirst_; because that in this case nothing is more requisite for us to know, then that we _want drink_ for the _Preservation_ of our _Health_. So of the Rest.
From all which ’tis manifest, that (notwithstanding the _infinite Goodness_ of God) ’tis impossible but the _Nature_ of _Man_ as he consists of a _mind_ and _body_ should be _deceivable_. For if any cause should excite (not in the Foot but) in the Brain it self, or in any other part through which the Nerves are continued from the Foot to the Brain, that _self same_ motion, which uses to arise from the Foot being troubled, the _Pain_ would be felt _as in the Foot_, and the _sense_ would be _naturally_ deceived; for ’tis consonant to Reason (seeing that That same motion of the Brain alwayes represents to the mind that same sense, and it oftner proceeds from a cause _hurtful_ to the _Foot_, than from any other) I say ’tis reasonable, that it should make known to the _mind_ the Pain of the _Foot_, rather than of any other _part_. And so if a _dryness_ of _Throat_ arises (not as ’tis used from the _necessity_ of _drink_ for the _conservation_ of the _Body_, but) from an _unusual Cause_, as it happens in a _Dropsie_, ’tis far better that it should _then deceive us_; then that it should _alwayes deceive_ us when the _Body_ is in _Health_, and so of the Rest.
And this consideration helps me very much, not only to _understand_ the _Errors_ to which my _Nature_ is subject, but also to _correct_ and _avoid_ them. For seeing I know that all my _Senses_ do oftener inform me _falsly_ than _truely_ in those things which conduce to the _Bodies advantage_; and seeing I can use (almost alwayes) more of them than one to _Examine_ the same thing, as also I can use _memory_, which joyns present and past things together, and my _understanding_ also, which hath already discovered to me all the _causes_ of my _Errors_, I ought no longer to fear, that what my _Senses_ daily represent to me should be false. But especially those _extravagant Doubts_ of my First Meditation are to be turn’d off as ridiculous; and perticularly the _chief_ of them, _viz_.
That * of not _distinguishing Sleep_ from _Waking_, for now I plainly discover a great _difference_, between them, for my _Dreams_ are never _conjoyned_ by my _memory_ with the other _actions_ of _my life_, as whatever happens to me _awake_ is; and certainly if (while I were awake) any person should suddenly appear to me, and presently disappear (as in _Dreams_) so that I could not tell _from whence_ he came or _where_ he went, I should rather esteem it a _Spectre_ or _Apparition feign’d_ in my Brain, then a _true Man_; but when such things occur, as I distinctly know from _whence_, _where_, and _when_ they come, and I _conjoyn_ the _perception_ of them by my _memory_ with the other _Accidents_ of my _life_, I am _certain_ they are represented to me _waking_ and not _asleep_, neither ought I in the least to doubt of their _Truth_, if after I have called up all my _senses_, _memory_, and _understanding_ to their _Examination_ I find nothing in any of them, that clashes with other truths; For _God_ not being a _Deceiver_, it follows, that In such things I am not _deceived_. But because the _urgency_ of _Action_ in the common _occurrences_ of _Affairs_ will not alwayes allow time for such an _accurate examination_, I must confess that _Mans life_ is _subject_ to many _Errors_ about _perticulars_, so that the _infirmity_ of our _Nature_ must be _acknowledged_ by Us.
Text from Project Gutenberg, public domain in the United States.