somewhat different from the usual. By the term impression, then, I
mean all our more lively perceptions, when we hear, or see, or feel,
or love, or hate, or desire, or will. And impressions are
distinguished from ideas, which are the less lively perceptions, of
which we are conscious, when we reflect on any of those sensations
or movements above mentioned.

  13. Nothing, at first view, may seem more unbounded than the thought
of man, which not only escapes all human power and authority, but is
not even restrained within the limits of nature and reality. To form
monsters, and join incongruous shapes and appearances, costs the
imagination no more trouble than to conceive the most natural and
familiar objects. And while the body is confined to one planet,
along which it creeps with pain and difficulty; the thought can in
an instant transport us into the most distant regions of the universe;
or even beyond the universe, into the unbounded chaos, where nature is
supposed to lie in total confusion. What never was seen, or heard
of, may yet be conceived; nor is any thing beyond the power of
thought, except what implies an absolute contradiction.

  But though our thought seems to possess this unbounded liberty, we
shall find, upon a nearer examination, that it is really confined
within very narrow limits, and that all this creative power of the
mind amounts to no more than the faculty of compounding,
transposing, augmenting, or diminishing the materials afforded us by
the senses and experience. When we think of a golden mountain, we only
join two consistent ideas, gold, and mountain, with which we were
formerly acquainted. A virtuous horse we can conceive; because, from
our own feeling, we can conceive virtue; and this we may unite to
the figure and shape of a horse, which is an animal familiar to us. In
short, all the materials of thinking are derived either from our
outward or inward sentiment: the mixture and composition of these
belongs alone to the mind and will. Or, to express myself in
philosophical language, all our ideas or more feeble perceptions are
copies of our impressions or more lively ones.

  14. To prove this, the two following arguments will, I hope, be
sufficient. First, when we analyze our thoughts or ideas, however
compounded or sublime, we always find that they resolve themselves
into such simple ideas as were copied from a precedent feeling or
sentiment. Even those ideas, which, at first view, seem the most
wide of this origin, are found, upon a nearer scrutiny, to be
derived from it. The idea of God, as meaning an infinitely
intelligent, wise, and good Being, arises from reflecting on the
operations of our own mind, and augmenting, without limit, those
qualities of goodness and wisdom. We may prosecute this enquiry to
what length we please; where we shall always find, that every idea
which we examine is copied from a similar impression. Those who
would assert that this position is not universally true nor without
exception, have only one, and that an easy method of refuting it; by
producing that idea, which, in their opinion, is not derived from this
source. It will then be incumbent on us, if we would maintain our
doctrine, to produce the impression, or lively perception, which
corresponds to it.

  15. Secondly. If it happen, from a defect of the organ, that a man
is not susceptible of any species of sensation, we always find that he
is as little susceptible of the correspondent ideas. A blind man can
form no notion of colours; a deaf man of sounds. Restore either of
them that sense in which he is deficient; by opening this new inlet
for his sensations, you also open an inlet for the ideas; and he finds
no difficulty in conceiving these objects. The case is the same, if
the object, proper for exciting any sensation, has never been
applied to the organ. A Laplander or Negro has no notion of the relish
of wine. And though there are few or no instances of a like deficiency
in the mind, where a person has never felt or is wholly incapable of a
sentiment or passion that belongs to his species; yet we find the same
observation to take place in a less degree. A man of mild manners
can form no idea of inveterate revenge or cruelty; nor can a selfish
heart easily conceive the heights of friendship and generosity. It
is readily allowed, that other beings may possess many senses of which
we can have no conception; because the ideas of them have never been
introduced to us in the only manner by which an idea can have access
to the mind, to wit, by the actual feeling and sensation.

  16. There is, however, one contradictory phenomenon, which may prove
that it is not absolutely impossible for ideas to arise, independent
of their correspondent impressions. I believe it will readily be
allowed, that the several distinct ideas of colour, which enter by the
eye, or those of sound, which are conveyed by the ear, are really
different from each other; though, at the same time, resembling. Now
if this be true of different colours, it must be no less so of the
different shades of the same colour; and each shade produces a
distinct idea, independent of the rest. For if this should be
denied, it is possible, by the continual gradation of shades, to run a
colour insensibly into what is most remote from it; and if you will
not allow any of the means to be different, you cannot, without
absurdity, deny the extremes to be the same. Suppose, therefore, a
person to have enjoyed his sight for thirty years, and to have
become perfectly acquainted with colours of all kinds except one
particular shade of blue, for instance, which it never has been his
fortune to meet with. Let all the different shades of that colour,
except that single one, be placed before him, descending gradually
from the deepest to the lightest; it is plain that he will perceive
a blank, where that shade is wanting, and will be sensible that
there is a greater distance in that place between the contiguous
colours than in any other. Now I ask, whether it be possible for
him, from his own imagination, to supply this deficiency, and raise up
to himself the idea of that particular shade, though it had never been
conveyed to him by his senses? I believe there are few but will be