into a cube, the other a figure of five sides.  In which incomplete ideas, we are very apt to impose on ourselves, and wrangle with others, especially where they have particular and familiar names.  For, being satisfied in that part of the idea which we have clear; and the name which is familiar to us, being applied to the whole, containing that part also which is imperfect and obscure, we are apt to use it for that confused part, and draw deductions from it in the obscure part of its signification, as confidently as we do from the other.

15.  Instance in Eternity.

Having frequently in our mouths the name Eternity, we are apt to think we have a positive comprehensive idea of it, which is as much as to say, that there is no part of that duration which is not clearly contained in our idea.  It is true that he that thinks so may have a clear idea of duration; he may also have a clear idea of a very great length of duration; he may also have a clear idea of the comparison of that great one with still a greater:  but it not being possible for him to include in his idea of any duration, let it be as great as it will, the whole extent together of A duration, where he supposes no end, that part of his idea, which is still beyond the bounds of that large duration he represents to his own thoughts, is very obscure and undetermined.  And hence it is that in disputes and reasonings concerning eternity, or any other infinite, we are very apt to blunder, and involve ourselves in manifest absurdities.

16.  Infinite Divisibility of Matter.

In matter, we have no clear ideas of the smallness of parts much beyond the smallest that occur to any of our senses:  and therefore, when we talk of the divisibility of matter in infinitum, though we have clear ideas of division and divisibility, and have also clear ideas of parts made out of a whole by division; yet we have but very obscure and confused ideas of corpuscles, or minute bodies, so to be divided, when, by former divisions, they are reduced to a smallness much exceeding the perception of any of our senses; and so all that we have clear and distinct ideas of is of what division in general or abstractedly is, and the relation of TOTUM and pars:  but of the bulk of the body, to be thus infinitely divided after certain progressions, I think, we have no clear nor distinct idea at all.  For I ask any one, whether, taking the smallest atom of dust he ever saw, he has any distinct idea (bating still the number, which concerns not extension) betwixt the 100,000th and the 1,000,000th part of it.  Or if he think he can refine his ideas to that degree, without losing sight of them, let him add ten cyphers to each of those numbers.  Such a degree of smallness is not unreasonable to be supposed; since a division carried on so far brings it no nearer the end of infinite division, than the first division into two halves does.