that which usually men attain to: and when we denominate him old, we mean that his duration is run out almost to the end of that which men do not usually exceed. And so it is but comparing the particular age or duration of this or that man to the idea of that 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 mind 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 has 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 thereto, 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 place and extension.-The Relation also that things have to one another in their places and distances is very obvious to observe; as, above, below, a mile distant, in England, in London, &c. But as in duration, so in extension and bulk, there are some ideas that are relative, which we signify by names that are

thought positive; as, great and little are truly Relations.

And so abundance of words, in ordinary speech, stand only for Relations (and perhaps the greatest part), which at first sight seem to have no such signification: v. g. [in the sentence,] The ship has necessary stores'-necessary and stores are both relative words; one having a relation to the accomplishing the voyage intended, and the other to future use. [As to] all which Relations, how they are confined to and terminate in ideas derived from Sensation or Reflection, is too obvious to need any explication.

CHAPTER XXVII.

OF IDENTITY AND DIVERSITY.

Wherein identity consists.-Another occasion the mind often takes of comparing is,-the very being of things; when, considering any thing as existing at any determined time and place, we compare it with itself existing at another time, and thereon form the ideas of Identity and Diversity: and in this consists Identity-when the ideas it is attributed to vary not at all from what they were [at] that moment wherein we consider their former existence, and to which we compare the present.

Identity of substances. We have the ideas but of three sorts of Substances; 1. God. 2. Finite intelligences. 3. Bodies. First, God is without beginning, eternal, unalterable, and everywhere; and therefore concerning His Identity, there can be no doubt. Secondly, Finite

Spirits having had each its determinate time and place of beginning to exist, the relation to that time and place will always determine to each of them its Identity as long as it exists. Thirdly, The same will hold of every particle of matter, to which no addition or subtraction of matter being made, it is the same.

Identity of Modes [and Relations].—All other things being but Modes or Relations ultimately terminated in Substances, the Identity and Diversity of each particular existence of them, too, will be by the same way determined: only as to things whose existence is in succession, such as are the actions of finite beings, v. g. motion and thought, both which consist in a continued train of succession, concerning their diversity there can be no question; because, each perishing the moment it begins, they cannot exist in different times, or in different places, as permanent beings can at different times exist in distant places; and therefore no motion or thought, considered as at different times, can be the same, each part thereof having a different beginning of existence.

Identity of vegetables. We must [next] consider wherein [a plant] differs from a mass of matter; and that seems to me to be in this: That the one is only the cohesion of particles of matter any how united; the other such a disposition of them as constitutes the parts of [a plant], and such an organization of those parts as is fit to receive and distribute nourishment, so as to continue and frame [suppose] the wood, bark, and leaves, &c. of an oak, in which consists the vegetable life. That being then one plant which has such an organization of parts in one coherent body, partaking of one common life, it

continues to be the same plant as long as it partakes of the same life, though that life be communicated to new particles of matter vitally united to the living plant in a like continued organization, conformable to that sort of plant. For this organization, being at any one instant in any one collection of matter, is in that particular concrete distinguished from all other; and is that individual life which, existing constantly from that moment both forwards and backwards, in the same continuity of insensibly succeeding parts united to the living body of the plant, has that Identity which makes the same plant, and all the parts of it parts of the same plant, during all the time that they exist united in that continued organization, which is fit to convey that common life to all the parts so united.

Identity of animals.-The case is not so much different in brutes but that any one may hence see what makes an animal, and continues it the same. Something we have like this in machines, and [which] may serve to illustrate it. For example: What is a watch? It is plain it is nothing but a fit organization or construction of parts to a certain end, which, when a sufficient force is added to it, it is capable to attain. If we would suppose this machine one continued body, all whose organized parts were repaired, increased, or diminished, by a constant addition or separation of insensible parts, with one common life, we should have something very much like the body of an animal, with this difference,—that in an animal the fitness of the organization, and the motion wherein life consists, begin together, the motion coming from within; but in machines, the force coming sensibly

from without, is often away when the organ is in order, and well fitted to receive it.

Identity of man. This also shows wherein the Identity of the same man consists; viz. in nothing but-a participation of the same continued life, by constantly fleeting particles of matter, in succession vitally united to the same organised body. If [as some suppose] Identity of soul alone makes the same man, and there be nothing in the nature of matter why the same individual spirit may not be united to different bodies, it will be possible that those men living in distant ages, and of different tempers, may have been the same man: which way of speaking must be from a very strange use of the word man, applied to an idea out of which body and shape [are] excluded.

Identity suited to the idea. It is not therefore unity of Substance that comprehends all sorts of Identity, or will determine it in every case: but, to conceive and judge of it aright, we must consider what idea the word it is applied to stands for: it being one thing to be the same substance, another the same man, and a third the same person, if person, man, and substance, are three names standing for three different ideas; for such as is the idea belonging to that name, such must be the Identity: which, if it had been a little more carefully attended to, would possibly have prevented a great deal of that confusion which often occurs about this matter, with no small seeming difficulties, especially concerning Personal Identity, which therefore we shall in the next place a little consider.

Personal identity.-To find wherein Personal Identity consists, we must consider what person stands for;