BOOK I PART IV
ceived, after any manner, may exist after the
same manner. This is one principle, which
has been already acknowledged. Again, ev-
ery thing, which is different, is distinguish-
able, and every thing which is distinguishable,
is separable by the imagination. This is an-
other principle. My conclusion from both is,
that since all our perceptions are different from
each other, and from every thing else in the uni-
verse, they are also distinct and separable, and
may be considered as separately existent, and
may exist separately, and have no need of any
thing else to support their existence. They are,
therefore, substances, as far as this definition
explains a substance.
Thus neither by considering the first origin
of ideas, nor by means of a definition are we
able to arrive at any satisfactory notion of sub-