ideas, which are different, are separable. For
it follows from thence, that if the figure be different from the body,
their ideas must be separable as well as distinguishable: if they be
not different, their ideas can neither be separable nor distinguishable.
What then is meant by a distinction of reason, since it implies neither
a difference nor separation.

To remove this difficulty we must have recourse to the foregoing
explication of abstract ideas. It is certain that the mind would never
have dreamed of distinguishing a figure from the body figured, as being
in reality neither distinguishable, nor different, nor separable; did it
not observe, that even in this simplicity there might be contained many
different resemblances and relations. Thus when a globe of white marble
is presented, we receive only the impression of a white colour disposed
in a certain form, nor are we able to separate and distinguish the
colour from the form. But observing afterwards a globe of black marble
and a cube of white, and comparing them with our former object, we
find two separate resemblances, in what formerly seemed, and really is,
perfectly inseparable. After a little more practice of this kind, we
begin to distinguish the figure from the colour by a distinction of
reason; that is, we consider the figure and colour together, since they
are in effect the same and undistinguishable; but still view them in
different aspects, according to the resemblances, of which they are
susceptible. When we would consider only the figure of the globe of
white marble, we form in reality an idea both of the figure and colour,
but tacitly carry our eye to its resemblance with the globe of black
marble: And in the same manner, when we would consider its colour only,
we turn our view to its resemblance with the cube of white marble. By
this means we accompany our ideas with a kind of reflection, of which
custom renders us, in a great measure, insensible. A person, who desires
us to consider the figure of a globe of white marble without thinking on
its colour, desires an impossibility but his meaning is, that we should
consider the figure and colour together, but still keep in our eye the
resemblance to the globe of black marble, or that to any other globe of
whatever colour or substance.

PART II. OF THE IDEAS OF SPACE AND TIME.

SECT. I. OF THE INFINITE DIVISIBILITY OF OUR IDEAS OF SPACE AND TIME.

Whatever has the air of a paradox, a