impression of the surrounding objects.

We must form a parallel supposition concerning the objects of our
feeling. It is not proper to suppose a perfect removal of all tangible
objects: we must allow something to be perceived by the feeling; and
after an interval and motion of the hand or other organ of sensation,
another object of the touch to be met with; and upon leaving that,
another; and so on, as often as we please. The question is, whether these
intervals do not afford us the idea of extension without body?

To begin with the first case; it is evident, that when only two luminous
bodies appear to the eye, we can perceive, whether they be conjoined or
separate: whether they be separated by a great or small distance; and if
this distance varies, we can perceive its increase or diminution, with
the motion of the bodies. But as the distance is not in this case any
thing coloured or visible, it may be thought that there is here a vacuum
or pure extension, not only intelligible to the mind, but obvious to the
very senses.

This is our natural and most familiar way of thinking; but which we shall
learn to correct by a little reflection. We may observe, that when two
bodies present themselves, where there was formerly an entire darkness,
the only change, that is discoverable, is in the appearance of these two
objects, and that all the rest continues to be as before, a perfect
negation of light, and of every coloured or visible object. This is not
only true of what may be said to be remote from these bodies, but also of
the very distance; which is interposed betwixt them; that being nothing
but darkness, or the negation of light; without parts, without
composition, invariable and indivisible. Now since this distance causes
no perception different from what a blind man receives from his eyes, or