TRANSCENDENTAL SCIENCE IN THE HUMAN INTELLECTUAL ORDER CANNOT EMANATE
FROM THE SENSES.
53. In the human intellectual order, such as it is in this life, there
is no one truth from which all others flow: philosophers have sought
one in vain; they have found none, for there was none to be found. In
fact, where could it be found?
54. Would it emanate from the senses?
Sensations are as various as the objects which produce them: by them we
acquire knowledge of individual and material things; but no one truth,
source of all other truths, can be found in any one of these, or the
sensations proceeding from them.
55. If we observe our impressions received through sensation, we shall
perceive that they are all equal so far as the production of certainty
is concerned. We are just as certain of the sensation caused by any
noise whatever, as we are of that produced by an object which we see,
an odorous body which we smell, a savory morsel which we taste, or any
thing which strongly affects our sense of touch. There is no gradation
in the certainty produced by these sensations: they are all equal; for
if we speak of sensation itself, we experience it in such a manner as
to leave no uncertainty; and if we speak of the relation of sensation
with the existence of the object causing it, we are just as certain
that the sensation called _sight_ corresponds to an external object
_seen_, as we are that an external object _touched_ corresponds to the
sensation called _touch_.
Hence we infer that no one sensation is the origin of the certainty
of other sensations; in this they are all alike: and most men have no
other reason than their experience why they should be sure of this
certainty. We are aware that what happens to individuals from whose
eyes cataracts have been removed, shows that simple sensation does not
suffice for the due appreciation of the object perceived, and that
one sense aids another: but this does not prove any one of them to be
preferable; for as the blind man, whose sight was suddenly restored,
did not form an exact judgment as to the size and distance of objects
seen by sight only, but required the assistance of touch; so is it
very probable that if a person of good eyesight had been deprived
from his birth of the sense of touch, he would not be able, were this
sense given him suddenly, to form an exact judgment concerning objects
touched, until, by the aid of sight, he had become accustomed to
combine the new and the old order of sensations, and learnt by practice
to determine the relations of sensation with its object, or to know by
sensation the properties of its object.
56. This fact of the blind man is however contradicted by others which
lead to a directly opposite result. The youth, upon whom the oculist,
Jean Janin, performed the same operation, and other persons blind from
their birth, whose eyesight Luigi de' Gregori partly restored, did not,
like the blind man of Cheselden, deem these objects stuck to their
eyes, but that they saw them as things really external and separate.
Rosmini thus relates it,[3] although he gives the preference to the
Cheselden case, which he says was repeated in Italy by the professor
Giacomo di Pavia with precisely the same results.
[3] _Saggio sull' origine delle idee_, p. 5, c. iv., tr. 11, p. 285,
where he cites the theoretico-chemical observations on the cataracts
of those born blind, by Luigi de' Gregori, professor of chemistry and
opthalmia, published at Rome in 1826.
57. It is not easy to ascertain how this combination of one sensation
with another enables us to judge rightly of external objects; chiefly
because the development of our sensitive and intellectual faculties is
completed before we can reflect upon it: and thus we find ourselves
certain of the existence and properties of things before we have
thought of certainty, and much less of the means of acquiring it.
58. But even supposing us, after occupying ourselves with sensations
and their relations with objects, to set aside the certainty which
we already have, and to act as if we sought it, we can find no one
sensation the basis of the certainty of the other sensations. We should
meet in that all the difficulties to be encountered in the others.
59. One of the chief difficulties upon this point is to determine the
relations of the sense of sight with that of touch, and how far the one
depends upon the other. We propose hereafter to examine these questions
at some length, and we shall therefore now refrain from entering upon
them, as well because they are not of a character to be incidentally
investigated, as because whatever their solution, it is not at all
opposed to what we shall here establish.
60. It would be of no advantage to us to know that the certainty of
all sensations was, philosophically speaking, founded upon that of
some one sensation. Every sensation is a contingent, individual fact:
how then are we to draw from it light to guide us to necessary truths?
No matter under what aspect we consider sensation, it is only an
impression received through our organs. We are sure of the impression
because it is intimately present to our mind; and its repetition aided
by other sensations, whether of the same or another sense, makes us
certain of its relations with the object producing it: but every thing
is done instinctively, with little or no reflection; and we are always
condemned, however much we reflect, to reach a point beyond which we
cannot pass, for nature herself there stops us.
61. Far then from finding in any sensation a fundamental fact on
which to found a philosophical certainty, we discover a collection of
particular and mutually distinct facts, equal, however, so far as the
production in us of that security which we call certainty is concerned.
It is of no use to decompose man, and reduce him first to an inanimate
machine, then allow him one sense, making him perceive different
sensations, afterwards grant him another sense, making him combine the
new and the old sensations, and so on synthetically to the possession
and exercise of them all. These things may do to entertain one's
curiosity, to nourish philosophical pretensions, or to give a show of
probability to imaginary systems; but they are in reality of little
or no use; the evolutions which the observer imagines do not resemble
those of nature; and the true philosopher ought to examine what really
is, not what is only in his conception.
Condillac, animating his statue by degrees, and making the whole sum
of human knowledge flow from one sensation, is like those priests who
got inside the statue of the idol, and thence emitted their oracles.
It is not the statue which receives animation, that speaks and thinks,
it is Condillac from within it. Let us, however, grant to the sensist
all he demands; let us allow him to regulate as he pleases the mutual
dependence of sensations; for the instant we require him to make
use only of pure sensations in his discussions, he will be utterly
disconcerted, how much soever he may suppose them to be transformed.
But we reserve these questions to the place in which we shall examine
the nature and origin of ideas.
62. Why are we sure that the agreeable sensation which we experience
in our sense of smell proceeds from an object called a _rose_? Because
we recollect having experienced the same sensation on a thousand other
occasions; because both sight and touch confirm the testimony of smell.
But how do we know that these sensations are something beside the
impressions received in our soul? Why may we not believe them to come
from some cause or other, without relation to external causes? Is it
because other men say the contrary? Are we certain that they exist? How
do they know what they tell us? How do we know that we hear rightly?
There is the same difficulty with the other senses as with that of
hearing, and if we doubt the testimony of three senses, why shall we
not doubt that of four? Reasoning is here of no avail; it would lead us
to cavils which would require an impassible doubt, and would tear from
us a security, of which, notwithstanding all our efforts, we cannot
despoil ourselves.
Moreover, if we appeal to the principles of reason, in order to prove
the truth of sensation, we leave the territory of sensations, and do
not place in them the primitive truth, origin of all other truths, nor
accomplish what we undertook.
63. Hence it follows: First, that there is no one sensation which is
the origin of the certainty of all others; this we have only indicated
here, reserving the demonstration of it to our treatise on sensations.
Secondly, although such a sensation were to exist, it could not serve
as the basis of any thing in the intellectual order, for with sensation
alone it is impossible even to think. Thirdly, that sensations, so far
from being able to serve as the basis of transcendental science, cannot
serve of themselves alone to establish any science; because necessary
truths cannot flow from them, since they are contingent facts.(5)