duration which we have in our minds, as ordinarily belonging to that sort of animals: which is plain in the application of these names to other things; for a man is called young at twenty years, and very young at seven years old: but yet a horse we call old at twenty, and a dog at seven years, because in each of these we compare their age to different ideas of duration, which are settled in our minds as belonging to these several sorts of animals, in the ordinary course of nature. But the sun and stars, though they have outlasted several generations of men, we call not old, because we do not know what period God hath set to that sort of beings. This term belonging properly to those things which we can observe in the ordinary course of things, by a natural decay, to come to an end in a certain period of time; and so have in our minds, as it were, a standard to which we can compare the several parts of their duration; and, by the relation they bear thereunto, call them young or old; which we cannot, therefore, do to a ruby or a diamond, things whose usual periods we know not.
Relations of