ties to that abstract complex idea, to which that name is annexed. But this distinction of essences belonging particularly to substances, we shall, when we come to consider their names, have an occasion to treat of more fully.

Essences in- §. 19. That such abstract ideas, with

generable and incor

ruptible.

names to them, as we have been speaking of, are essences, may farther appear by what we are told concerning essences, viz. that they are all ingenerable and incorruptible. Which cannot be true of the real constitutions of things which begin and perish with them. All things that exist, besides their author, are all liable to change; especially those things we are acquainted with, and have ranked into bands under distinct names or ensigns. Thus that which was grass to-day, is to-morrow the flesh of a sheep; and within a few days after becomes part of a man in all which, and the like changes, it is evident their real essence, i. e. that constitution, whereon the properties of these several things depended, is destroyed and perishes with them. But essences being taken for ideas, established in the mind, with names annexed to them, they are supposed to remain steadily the same, whatever mutations the particular substances are liable to. For whatever becomes of Alexander and Bucephalus, the ideas to which man and horse are annexed, are supposed nevertheless to remain the same; and so the essences of those species are preserved whole and undestroyed, whatever changes happen to any, or all of the individuals of those species. By this means the essence of a species rests safe and entire, without the ex; istence of so much as one individual of that kind. For were there now no circle existing any where in the world, (as perhaps that figure exists not any where exactly marked out) yet the idea annexed to that name would not cease to be what it is; nor cease to be as pattern to determine which of the particular figures we meet with have or have not a right to the name circle, and so to show which of them by having that essence, was of that species. And though there neither were nor had been in nature such a beast as an unicorn, or

such

such a fish as a mermaid; yet supposing those names to stand for complex abstract ideas that contained no inconsistency in them, the essence of a mermaid is as intelligible as that of a man; and the idea of an unicorn as certain, steady, and permanent as that of a horse. From what has been said it is evident, that the doctrine of the immutability of essences proves them to be only abstract ideas; and is founded on the relation established between them, and certain sounds as signs of them; and will always be true as long as the same name can have the same signification.

$20. To conclude, this is that which in Recapitula short I would say, viz. that all the great tion. business of genera and species, and their essences, amounts to no more but this, That men making abstract ideas, and settling them in their minds with names annexed to them, do thereby enable themselves to consider things, and discourse of them as it were in bundles, for the easier and readier improvement and communication of their knowledge; which would advance but slowly, were their words and thoughts confined only to particulars.

THO

Of the Names of Simple Ideas.

HOUGH all words, as I have shown, signify nothing immediately but the ideas in the mind of the

Names of simple ideas, modes, and

substances,

have each something peculiar.

speaker; yet upon a nearer survey we shall find that the names of simple ideas, mixed modes, (under which I comprise relations too) and natural substances, have each of them something peculiar and different from the other. ample:

§. 2. First, The names of simple ideas and substances, with the abstract ideas in the mind, which they immediately signify,

Gg3

For ex

1. Names of

simple ideas

and sub

intimate

stances inti. mate real existence.

intimate also some real existence, from which was derived their original pattern. But the names of mixed modes terminate in the idea that is in the mind, and lead not the thoughts any farther, as we shall see more at large in the following chapter.

z. Names of simple ideas and modes signify at.. ways both real and

3. Secondly, The names of simple ideas and modes signify always the real as well as nominal essence of their species. But the names of natural substances signify rarely, if ever, any thing but barely the nominal essences of those species; as we shall show in the chapter that treats of the names of substances in particular.

nominal es

sence.

It has

§. 4. Thirdly, The names of simple 3. Names of ideas are not capable of any definition; the simple ideas undefinable. names of all complex ideas are. not, that I know, been yet observed by any body, what words are, and what are not capable of being defined; the want whereof is (as I am apt to think) not seldom the occasion of great wrangling and obscurity in men's discourses, whilst some demand definitions of terms that cannot be defined; and others think they ought not to rest satisfied in an explication made by a more general word, and its restriction, (or, to speak in terms of art, by a genus and difference) when even after such definition made according to rule, those who hear it have often no more a clear conception of the meaning of the word than they had before. This at least I think, that the showing what words are, and what are not capable of definitions, and wherein consists a good definition, is not wholly besides our present purpose; and perhaps will afford so much light to the nature of these signs, and our ideas, as to deserve a more particular consideration.

-If all were definable, it would be a process in infinitum.

5. I will not here trouble myself to prove that all terms are 'not definable from that progress in infinitum, which it will visibly lead us into, if we should allow that all names could be defined. For if the terms of one definition were still to be defined by

another,

another, where at last should we stop? But I shall from the nature of our ideas, and the signification of our words, show, why some names can, and others cannot be defined, and which they are.

What a defi

nition is.

§. 6. I think it is agreed, that a definition is nothing else but the showing the meaning of one word by several other not synonimous terms. The meaning of words being only the ideas they are made to stand for by him that uses them, the meaning of any term is then showed, or the word is defined, when by other words the idea it is made the sign of, and annexed to, in the mind of the speaker, is as it were represented, or set before the view of another; and thus its signification ascertained: this is the only use and end of definitions; and therefore the only measure of what is, or is not a good defi nition.

Simple ideas why unde

finable.

Instances;

§. 7. This being premised, I say, that the names of simple ideas, and those only are incapable of being defined. The reason whereof is this, that the several terms of a definition, signifying several ideas, they can all together by no means represent an idea, which has no composition at all: and therefore definition, which is properly nothing but the showing the meaning of one word by several others not signifying each the same thing, can in the names of simple ideas have no place. §. 8. The not observing this difference in our ideas, and their names, has pro- motion. duced that eminent trifling in the schools, which is so easy to be observed in the definitions they give us of some few of these simple ideas. For as to the greatest part of them, even those masters of definitions were fain to leave them untouched, merely by the impossibility they found in it. What more exquisite jargon could the wit of man invent, than this definition, "The act of a being in power, as far forth as in power?" which would puzzle any rational man, to whom it was not already known by its famous absurdity, to guess what word it could ever be supposed to be the explication of. If Tully, asking a Dutchman Gg 4

what

what "beweeginge" was, should have received this explication in his own language, that it was "actus "entis in potentia quatenus in potentia ;" I ask whether any one can imagine he could thereby have understood what the word " beweeginge" signified, or have guessed what idea a Dutchman ordinarily had in his mind, and would signify to another, when he used that sound.

§. 9. Nor have the modern philosophers, who have endeavoured to throw off the jargon of the schools, and speak intelligibly, much better succeeded in defining simple ideas, whether by explaining their causes, or any otherwise. The atomists, who define motion to be a passage from one place to another, what do they more than put one synonymous word for another? For what is passage other than motion? And if they were asked what passage was, how would they better define it than by motion? For is it not at least as proper and significant to say, passage is a motion from one place to another, as to say, motion is a passage, &c.? This is to translate, and not to define, when we change two words of the same signification one for another; which, when one is better understood than the other, may serve to discover what idea the unknown stands for; but is very far from a definition, unless we will say every English word in the dictionary is the definition of the Latin word it answers, and that motion is a definition of motus. Nor will the successive application of the parts of the superficies of one body to those of another, which the Cartesians give us, prove a much better definition of motion, when well examined.

§. 10. "The act of perspicuous, as far Light. forth as perspicuous," is another peripatetic definition of a simple idea; which though not more absurd than the former of motion, yet betrays its uselessness and insignificancy more plainly, because experience will easily convince any one, that it cannot make the meaning of the word light (which it pretends to define) at all understood by a blind man; but the definition of motion appears not at first sight so useless, because it escapes this way of trial. For this simple idea, entering by the touch as well as sight, it is im possible