form.

Whoever opposes this, must necessarily point out that distinct
impression, from which the idea of entity is derived, and must prove,
that this impression is inseparable from every perception we believe to
be existent. This we may without hesitation conclude to be impossible.

Our foregoing reasoning [Part I. Sect. 7.] concerning the distinction of
ideas without any real difference will not here serve us in any stead.
That kind of distinction is founded on the different resemblances, which
the same simple idea may have to several different ideas. But no object
can be presented resembling some object with respect to its existence, and
different from others in the same particular; since every object, that is
presented, must necessarily be existent.

A like reasoning will account for the idea of external existence. We may
observe, that it is universally allowed by philosophers, and is besides
pretty obvious of itself, that nothing is ever really present with the
mind but its perceptions or impressions and ideas, and that external
objects become known to us only by those perceptions they occasion. To
hate, to love, to think, to feel, to see; all this is nothing but to
perceive.

Now since nothing is ever present to the mind but perceptions, and since
all ideas are derived from something antecedently present to the mind; it
follows, that it is impossible for us so much as to conceive or form an
idea of any thing specifically different. from ideas and impressions. Let
us fix our attention out of ourselves as much as possible: Let us chase
our imagination to the heavens, or to the utmost limits of the universe;
we never really advance a step beyond ourselves, nor can conceive any