BOOK I PART II
unaccompanyed with some other perception,
it can no more give us that idea, when mixed
with the impressions of tangible objects; since
that mixture produces no alteration upon it.
But though motion and darkness, either
alone, or attended with tangible and visible ob-
jects, convey no idea of a vacuum or extension
without matter, yet they are the causes why we
falsly imagine we can form such an idea. For
there is a close relation betwixt that motion and
darkness, and a real extension, or composition
of visible and tangible objects.
First, We may observe, that two visible ob-
jects appearing in the midst of utter darkness,
affect the senses in the same manner, and form
the same angle by the rays, which flow from
them, and meet in the eye, as if the distance
betwixt them were find with visible objects,