XV. The third ground for the said distrust, is derived from the erroneous
representation of things made by the imaginary faculty, which fancies
external sensations of objects that do not exist. Such, for example,
as the imagination of him who has had a leg cut off, representing to
him a pain in the leg or foot that has been amputated; or that of an
hypocondriac person, who fancies himself to be glass, earthen ware, a
wolf, or a dog, whose imagination represents those strange forms, as
evidently and manifestly palpable to his senses; so that he who fancies
himself glass, will swear with invincible firmness, that he perceives in
his own person the transparency, and feels on his own skin the smooth
surface, which is proper and peculiar to that artificial composition.
XVI. This error is common to all men in their wanderings when they are
asleep; because he who dreams, believes he perceives those objects with
his senses, which he only perceives with his imagination; and from hence,
the rigid sceptics deduce a most pernicious argument, by way of proving,
that we should doubt of every thing; because they say no man can be
positively certain, whether he is asleep or awake; according to which
mode of reasoning, no one can be certain, whether he sees, hears, or
touches any thing whatever; for notwithstanding his having the greatest
confidence that he is awake, it is possible that he may be sleeping; and
that the things which are represented to him as seen, heard, &c. are all
imaginary. For example, I consider myself as now writing, and reading
what I write. But what certainty have I that I am writing and reading?
Have not I dreamed a thousand times, that I was reading and writing? And
at those times, such occupations appeared to me, not as things that I was
dreaming of, but as exercises that I was really and actually practising;
and therefore, that may be the case with me at present.
XVII. I have said already, and with reason, that this argument is a most
pernicious and dangerous one; for whatever answer you make to it, your
adversary turns upon you, and urges the opposite opinion as forcibly,
as you can support your reply. At least I have never seen any solution
of this matter, which could more or less vanquish the force of the
difficulty. It has been objected to this sort of reasoning, that the
argument proves too much, and tends to involve in, and reduce to the
same state of doubt, all the sacred dogmas of religion. This remark is a
just one, for he who comes to doubt, whether all he hears or sees is not
a mere imaginary representation, must necessarily doubt of the reality
of all the instruction he has received, both with respect to religion,
and every other matter. But what advantage shall we gain, by insisting
upon this against a sceptic, whose intention perhaps is to destroy all
religion? And although he should not argue with this depraved view, but
should reply to these objections out of wantonness, or from motives of
vanity and ostentation, and a fondness of shewing his parts, it would be
wasting time to dispute with him, or to press the argument, because these
instances, notwithstanding they are good ones and may be fairly insisted
on, are not answers.
XVIII. It is certain there are some truths, that maugre the clearness and
confidence with which the understanding assents to them, are not exempt
from being exposed to difficult objections; or to speak more properly,
there is no truth whatever, be it ever so firmly established, against
which, some sophistical objection may not be raised. It would therefore
not be right upon all occasions, to give up a maxim, whose truth we
clearly perceive and are convinced of, only because we can’t reply to
every argument that may be urged against it. There are truths of such
a nature, that although they would strike, and be clear to any man of
ordinary understanding, still, the giving an answer to every objection
that could be raised against them, might possibly be found a difficult
task to a person of very subtil ingenuity. And notwithstanding we should
not be able to hit upon an argument, that would confront or silence those
which are used by the sceptics, to persuade us to doubt whether we are
sleeping or waking, we should not abandon ourselves to such a doubt, but
support ourselves in a firm confidence, that we are not mistaken with
respect to the state we are in. And in truth, the arguments used to make
us doubt of it, are not of such a nature, as that a clear, solid, and
unembarrassed answer may not be given to them.
XIX. And in order to do this, I shall begin with supposing, that evidence
in this case may be of two sorts, mediate, and immediate. An evident
proposition, supported by immediate evidence, is, when without the
assistance of any kind of proof, it presents itself so clearly to our
understandings, that the mind is constrained by invincible necessity to
assent to it. An evident proposition supported by mediate evidence, is,
when of itself, it is not represented to our understandings with all
this clearness, but is necessarily inferred from some other self-evident
proposition.
XX. I will suppose, secondly, that immediate evidence should be divided,
into metaphysical and experimental. The first is governed by universal
principles, which of themselves persuade or convince the understanding;
such as these, the whole is greater than a part; two contradictory
propositions can’t be both true at one and the same time. Experimental
evidence is derived from certain singular truths, which strike every
individual with infallible conviction; such as these, that I at present
have such or such a desire, or that I think of such or such a thing, that
I suffer some pain, or that I am affected with some particular sensation;
for example, joy, sadness, or anger.
XXI. That every individual feels this experimental evidence in some
particular instances, no one can doubt, and even if any person, by
giving to his scepticism all imaginable extension, should be desirous of
doubting of every thing, he could never stifle the experimental evidence
that he doubted. And here I can’t help remarking, that experimental
evidence is a thing of such moment to the Carthesians, that all their
metaphysical testimonies depend on, or are derived from it; because, from
that first maxim or proposition, I think, is inferred immediately, the
proof of their own existence; and mediately, all the other demonstrable
truths, are established upon experimental evidence only.
XXII. It is also certain, that from the truths which are established
upon experimental evidence, you can deduce no demonstrative reasoning;
or at least of that sort, which the logicians call _à priori_. The
reason is, because they are evident of themselves, or else are supported
by immediate evidence, and are not dependant upon any other thing
from whence they are inferred. Therefore, although for example, I at
present am convinced that I am desirous of eating such or such a thing,
I cannot persuade any other person that I fancy it, by any immediate
demonstration; because this is evident to me, not from any principle
that is notorious to all mankind, and from whence may be inferred
the existence of such a desire; but because the appetite itself, is
intimately connected with my spirit, and I feel it so forcibly, that
I cannot doubt of its existence: the same thing happens in the cases
of those truths, which are established upon immediate metaphysical
evidence. If I should be asked, how I know that the whole is greater
than one of its parts, I should answer, that I do not know it from any
principle from whence it may be inferred, but because the truth, _that
the whole is larger than a part_, is so clearly evident to my mind, that
it is as incompatible with doubt, as the light of the sun with midnight
darkness. If any one should deny to me, the truth of the maxim, that
two contradictory propositions cannot be both true at the same time, it
would be impossible for me to prove the truth of the maxim, either by
arguments deduced _à priori_, or _à posteriori_. The reason is plain,
because if I was to argue the point, the most I could do, would be
insisting on the manifest contradiction, and asserting the impossibility
of the thing, which is the last resource of logical dialect. But observe,
when we are got thus far, my adversary, to act consistently with his
first caprice, thinks fit to change his ground, and to admit both
extremes of the contradiction, and to insist they are both true. Now how,
in this case, am I to prove that they cannot be so? Why I can do it by no
other means, than by having recourse to the axiom, that it is impossible
two contradictory propositions can be both true at the same time. But
this is begging the question from the beginning, and proving what is
denied, by the same proposition which is the subject of the dispute.
XXIII. The suppositions we have just made, contain all the solutions we
are capable of giving, to the above argument. I say then, that I myself,
and I say the same of all others, who are in my present situation and
circumstances, have experimental Evidence that I am now awake: because
the state of wakefulness, which consists, in the intimate and ultimate
disposition of the faculties to exercise themselves in proper operations,
is an object, which presents itself to my mind, with such clearness,
that if I was never so desirous of doing it, I cannot entertain a doubt
of my being at present in that state; nor can any other reason be
required of me, nor can I give any other, for assenting to this truth;
neither can I for my assent to a first principle, give any other than the
beforementioned, nor alledge any other, to explain the existence of any
reflection, which my soul is at present intent upon.
XXIV. I will not however dissemble, that after this answer is given,
there still remains a serious difficulty to surmount, which may be
stated in the following manner. The experimental evidence, from whence
we deduce this persuasion, is fallacious; because when we sleep and
dream, we are under the same persuasion that we are awake, and our senses
then represent to us, that we are engaged in actual exercises in such a
manner, that if it was at that time to occur to us, to make reflection
upon what we were doing, we should conceive, that we had experimental
evidence of our speaking, seeing, hearing, &c. Therefore the idea that
I now entertain upon reflection, that I have at present experimental
evidence of my being at this instant awake, and engaged in study and
writing, affords me no absolute certainty that I am not asleep, or that I
am actually so employed.
XXV. This is the utmost extent to which the matter of doubting can be
carried. But by way of answer to it, I shall reply, that the persuasion
we have of being awake when we are dreaming, differs greatly from that
we have of being awake, when we actually are so. This last is a clear,
firm, determined, invincible persuasion, and such a one, as is required
to constitute experimental evidence of the certainty of the fact; which
it does in such a manner, that notwithstanding all the reflections we
can make, and all the doubts and difficulties we can suggest, our assent
to, and persuasion of the truth of it, remains firm and unshaken. On
the contrary, when we are dreaming, our reflection is obscure, and the
persuasion produced in consequence of it, feeble and wavering; which
will evidently appear to be the case, if in the course of our dreaming,
it should occur to us to make a doubtful reflection, whether what our
imagination represents to us is reality, or only a dream; and the result
to a man who was to do this would be, a faint and doubtful determination
of whether he actually dreams, or only believes he is dreaming, and he
would remain in a state of doubt, whether what his fancy represents to
him be real or not. I say in all these cases, his decision of the matter,
would not be resolute and firm, but wavering and languid. This doubt of
whether I am asleep or not, often occurs to me in dreams, which never
fails to produce one of the two following effects, either to certify to
me that I am dreaming, or to make me suspend my assent to the fact. And I
will venture to assure any one, who shall persist for a few moments, in
proposing these doubts to himself when he is dreaming, that he will find
the same thing happen to him.
XXVI. We may make use of the same reasoning, if the argument is applied to
the deliriums of maniacs. Every man, who after having been deprived of
his reason, comes to be restored to his senses, finds a great difference
with respect to the persuasions he feels, and the clearness of the
opinions he forms in a state of sanity, and those he entertained when he
was mad. Mad people seldom make any reflections, either on the state of
their mind, or the subject of their madness; and when they do happen to
make them, are generally more or less blinded by their apprehensions; of
which I myself have known some instances; and it has fallen in my way, by
the force of lively representations, first to prevail on some mad people
to doubt of the truth of their apprehensions, and afterwards to reason
them out of them; among whom there was a nun, who had been exceedingly
mad for some years, and whose life was thought to be in danger,
although in reality it was not so; and I being called to administer the
sacraments to her, was so happy as to reduce her mind to a state of
calmness, that rendered her capable of receiving them as a penitent. This
I accomplished, by using various reasonings and arguments, tending to
undeceive her, and at last was so fortunate as to hit upon one, adapted
to the nature of her disease, and the state of her mind, which had its
effect: but in doing this, great attention should be had to the tone of
the voice, and the energy and vivacity of the looks, and care should be
taken, that every action should be such, as is likely to give efficacy
and force to the arguments you use, in order that they should make an
impression on their minds; great caution should also be used not to
irritate them; and by these means, they are often brought to intervals
of sense; and although it is true, that they seldom last long, still the
gaining an hour of calm reason, is a matter of great importance, as it
was in the case of the nun we have just mentioned.
XXVII. The delicacy and curiosity of this subject, has caused me to dwell
on it longer than was necessary; for I am so far from apprehending, that
the arguments which are used in support of universal scepticism, will
prevail with, or have any weight on the world in general, that I do not
believe there ever yet was a man, who in reality was convinced by them.