ut should
I endeavour to clear up after the same manner any doubt in moral
philosophy, by placing myself in the same case with that which I
consider, it is evident this reflection and premeditation would so
disturb the operation of my natural principles, as must render it
impossible to form any just conclusion from the phenomenon. We must
therefore glean up our experiments in this science from a cautious
observation of human life, and take them as they appear in the common
course of the world, by men's behaviour in company, in affairs, and
in their pleasures. Where experiments of this kind are judiciously
collected and compared, we may hope to establish on them a science which
will not be inferior in certainty, and will be much superior in utility
to any other of human comprehension.

BOOK I. OF THE UNDERSTANDING

PART I. OF IDEAS, THEIR ORIGIN, COMPOSITION, CONNEXION, ABSTRACTION,
ETC.

SECT. I. OF THE ORIGIN OF OUR IDEAS.

All the perceptions of the human mind resolve themselves into two
distinct kinds, which I shall call IMPRESSIONS and IDEAS. The difference
betwixt these consists in the degrees of force and liveliness, with
which they strike upon the mind, and make their way into our thought
or consciousness. Those perceptions, which enter with most force and
violence, we may name impressions: and under this name I comprehend
all our sensations, passions and emotions, as they make their first
appearance in the soul. By ideas I mean the faint images of these in
thinking and reasoning; such as, for instance, are all the perceptions
excited by the present discourse, excepting only those which arise from
the sight and touch, and excepting the immediate pleasure or uneasiness
it may occasion. I believe it will not be very necessary to employ many
words in explaining this distinction. Every one of himself will readily
perceive the difference betwixt feeling and thinking. The common degrees
of these are easily distinguished; though it is not impossible but in
particular instances they may very nearly approach to each other. Thus
in sleep, in a fever, in madness, or in any very violent emotions of
soul, our ideas may approach to our impressions, As on the other hand
it sometimes happens, that our impressions are so faint and low, that
we cannot distinguish them from our ideas. But notwithstanding this near
resemblance in a few instances, they are in general so very different,
that no-one can make