An Enquiry Concerning Human Understanding HTML version

brought into dispute, by a certain species of philosophers; and the maxims of common
life are subjected to the same doubt as the most profound principles or conclusions of
metaphysics and theology. As these paradoxical tenets (if they may be called tenets) are
to be met with in some philosophers, and the refutation of them in several, they naturally
excite our curiosity, and make us enquire into the arguments, on which they may be
I need not insist upon the more trite topics, employed by the sceptics in all ages, against
the evidence of sense; such as those which are derived from the imperfection and
fallaciousness of our organs, on numberless occasions; the crooked appearance of an oar
in water; the various aspects of objects, according to their different distances; the double
images which arise from the pressing one eye; with many other appearances of a like
nature. These sceptical topics, indeed, are only sufficient to prove, that the senses alone
are not implicitly to be depended on; but that we must correct their evidence by reason,
and by considerations, derived from the nature of the medium, the distance of the object,
and the disposition of the organ, in order to render them, within their sphere, the proper
criteria of truth and falsehood. There are other more profound arguments against the
senses, which admit not of so easy a solution.
118. It seems evident, that men are carried, by a natural instinct or prepossession, to
repose faith in their senses; and that, without any reasoning, or even almost before the use
of reason, we always suppose an external universe, which depends not on our perception,
but would exist, though we and every sensible creature were absent or annihilated. Even
the animal creation are governed by a like opinion, and preserve this belief of external
objects, in all their thoughts, designs, and actions.
It seems also evident, that, when men follow this blind and powerful instinct of nature,
they always suppose the very images, presented by the senses, to be the external objects,
and never entertain any suspicion, that the one are nothing but representations of the
other. This very table, which we see white, and which we feel hard, is believed to exist,
independent of our perception, and to be something external to our mind, which perceives
it. Our presence bestows not being on it: our absence does not annihilate it. It preserves
its existence uniform and entire, independent of the situation of intelligent beings, who
perceive or contemplate it.
But this universal and primary opinion of all men is soon destroyed by the slightest
philosophy, which teaches us, that nothing can ever be present to the mind but an image
or perception, and that the senses are only the inlets, through which these images are
conveyed, without being able to produce any immediate intercourse between the mind
and the object. The table, which we see, seems to diminish, as we remove farther from it:
but the real table, which exists independent of us, suffers no alteration: it was, therefore,
nothing but its image, which was present to the mind. These are the obvious dictates of
reason; and no man, who reflects, ever doubted, that the existences, which we consider,
when we say, this house and that tree, are nothing but perceptions in the mind, and
fleeting copies or representations of other existences, which remain uniform and