Too Long; Didn't Read
1. Simple modes of simple ideas.
Though in the foregoing part I have often mentioned simple ideas, which are truly the materials of all our knowledge; yet having treated of them there, rather in the way that they come into the mind, than as distinguished from others more compounded, it will not be perhaps amiss to take a view of some of them again under this consideration, and examine those different modifications of the SAME idea; which the mind either finds in things existing, or is able to make within itself without the help of any extrinsical object, or any foreign suggestion.
Those modifications of any ONE simple idea (which, as has been said, I call SIMPLE MODES) are as perfectly different and distinct ideas in the mind as those of the greatest distance or contrariety. For the idea of two is as distinct from that of one, as blueness from heat, or either of them from any number: and yet it is made up only of that simple idea of an unit repeated; and repetitions of this kind joined together make those distinct simple modes, of a dozen, a gross, a million. Simple Modes of Idea of Space.
2. Idea of Space.
I shall begin with the simple idea of SPACE. I have showed above, chap. 4, that we get the idea of space, both by our sight and touch; which, I think, is so evident, that it would be as needless to go to prove that men perceive, by their sight, a distance between bodies of different colours, or between the parts of the same body, as that they see colours themselves: nor is it less obvious, that they can do so in the dark by feeling and touch.
3. Space and Extension.
This space, considered barely in length between any two beings, without considering anything else between them, is called DISTANCE: if considered in length, breadth, and thickness, I think it may be called CAPACITY. When considered between the extremities of matter, which fills the capacity of space with something solid, tangible, and moveable, it is properly called EXTENSION. And so extension is an idea belonging to body only; but space may, as is evident, be considered without it. At least I think it most intelligible, and the best way to avoid confusion, if we use the word extension for an affection of matter or the distance of the extremities of particular solid bodies; and space in the more general signification, for distance, with or without solid matter possessing it.