talk after others. But if it should happen that any two thinking men should really have different ideas, I do not see how they could discourse or argue one with another. Here I must not be mistaken, to think that every floating imagination in men's brains is presently of that sort of ideas I speak of. It is not easy for the mind to put off those confused notions and prejudices it has imbibed from custom, inadvertency, and common conversation: it requires pains and assiduity to examine its ideas, till it resolves them into those clear and distinct simple ones, out of which they are compounded; and to see which, amongst its simple ones, have or have not a necessary connexion and dependence one upon another. Till a man doth this in the primary and original notion of things, he builds upon floating and uncertain principles, and will often find himself at a loss.
CHAPTER XIV.
Of Duration, and its simple Modes.
Duration is fleeting extension.§ 1. There is another sort of distance or length, the idea whereof we get not from the permanent parts of space, but from the fleeting and perpetually perishing parts of succession. This we call duration, the simple modes whereof are any different lengths of it whereof we have distinct ideas, as hours, days, years, &c. time and eternity.
Its idea from reflection on the train of our ideas.§ 2. The answer of a great man to one asked what time was, "Si non rogas intelligo," (which amounts to this, the more I set myself to think of it, the less I understand it) might perhaps persuade one that time, which reveals all other things, is itself not to be dis-
