7. Difference between infinity of space, and space infinite.
Though our idea of infinity arise from the
contemplation of quantity, and the endless increase the mind is able to make in quantity, by the repeated additions
of what portions thereof it pleases; yet I guess we cause great confusion in our thoughts, when we join infinity to
any supposed idea of quantity the mind can be thought to have, and so discourse or reason about an infinite
quantity, as an infinite space, or an infinite duration. For, as our ideas of infinity being, as I think, an endless
growing idea, but the idea of any quantity the mind has, being at that time terminated in that idea, (for be it as
great as it will, it can be no greater than it is,)--to join infinity to it, is to adjust a standing measure to a growing
bulk; and therefore I think it is not an insignificant subtilty, if I say, that we are carefully to distinguish between
the idea of the infinity of space, and the idea of a space infinite. The first is nothing but a supposed endless
progression of the mind, over what repeated ideas of space it pleases; but to have actually in the mind the idea of a
space infinite, is to suppose the mind already passed over, and actually to have a view of all those repeated ideas
of space which an endless repetition can never totally represent to it; which carries in it a plain contradiction.
