— 215 —
Our different conception of the Infinity of Number, Duration, and Expansion.       §10. It will, perhaps, give us a little farther light into the Idea we
have of Infinity, and discover to us, that it is nothing but the Infinity of
Number applied to determinate parts, of which we have in our Minds the
distinct Ideas, if we consider that Number is not generally thought
by us infinite, whereas Duration and Extension are apt to be so;
which arises from hence, That in Number we are at one end as it
were: for there being in Number nothing less than an Unite, we
there stop, and are at an end; but in addition, or increase of Num-
ber, we can set no Bounds: and so it is like a Line, whereof one end
terminating with us, the other is extended still forwards beyond all
that we can conceive; but in Space and Duration it is otherwise.
For in Duration, we consider it, as if this Line of Number were
extended both ways to an unconceivable, undeterminate, and
infinite length; which is evident to any one, that will but reflect on
what Consideration he hath of Eternity; which, I suppose, he will
find to be nothing else, but the turning this Infinity of Number
both ways, à parte ante, and à parte post, as they speak. For when we
would consider Eternity, à parte ante, what do we but, beginning
from our selves, and the present time we are in, repeat in our
Minds the Ideas of Years, or Ages, or any other assignable Portion of
Duration past, with a prospect of proceeding, in such Addition,
with all the Infinity of Number; and when we would consider
— 216 —
Eternity, à parte post, we just after the same rate begin from our
selves, and reckon by multiplied Periods yet to come, still extend-
ing that Line of Number, as before; and these two being put
together, are that infinite Duration we call Eternity; which, as we
turn our view either way forwards or backwards, appears infinite,
because we still turn that way the infinite end of Number, i.e. the
Power still of adding more.
Locke Hum II, 17, §10, pp. 215-216