CHAPTER 15 Ideas of Duration and Expansion,Considered Together
1. Both capable of greater and less.
Though we have in the precedent chapters dwelt pretty long on the considerations of space and duration, yet, they being ideas of general concernment,that have something very abstruse and peculiar in their nature, the comparing them one with another may perhaps be of use for their illustration; and we may have the more clear and distinct conception of them by taking a view of them together. Distance or space,in its simple abstract conception, to avoid confusion,I call EXPANSION, to distinguish it from extension,which by some is used to express this distance only as it is in the solid parts of matter, and so includes, or at least intimates, the idea of body: whereas the idea of pure distance includes no such thing. I prefer also the word expansion to space, because space is often applied to distance of fleeting successive parts, which never exist together, as well as to those which are permanent. In both these (viz. expansion and duration) the mind has this common idea of continued lengths,capable of greater or less quantities. For a man has as clear an idea of the difference of the length of an hour and a day, as of an inch and a foot.