not with certainty affirm, that all men fleep by intervals; that no man can be nourished by wood or ftones; that all men wil be paifoned by hemlock; because these ideas have no connection nor repugnancy with this our nominal effence of man, with this ab ftract idea that name flands for. We muft in thefe and the like appeal to trial in particular fubjects, which can reach but a little way; we must content ourfelves with probability in the reft, but can have no general certainty, whilft our fpecific idea of mas contains not that real constitution, which is the root, wherein all his infeparable qualities are united, and from whence they flow. Whilft our idea, the word man ftands for, is only an imperfect collection of fome fenfible qualities and powers in him, there is no difcernible connection or repugnance between our specifie idea, and the operation of either the parts of hemlock or ftones upon his conftitution. There are animals that fafely eat hemlock, and others that are nourished by wood and ftones: But as long as we want ideas of thofe real conftitutions of different forts of animals, whereon thefe and the like qualities and powers depend, we must not hope to reach certainty in univerfal propofitions concerning them. Thofe few ideas only which have a difcernible connection with our nominal effence, or any part of it, can afford us fuch propofitions; but these are fo few, and of fo little moment, that we may justly look on our certain general knowledge of fubftances as almost none at all.

16. Wherein lies the general Certainty of Pro

pofitions.

To conclude, general propofitions, of what kind foever, are then only capable of certainty, when the terms used in them ftand for fuch ideas, whofe agreement or difagreement, as there exprefled, is capable to be discovered by us; and we are then certain of their truth or falfehood, when we perceive the ideas the terms ftand for, to agree or not agree, according as they are affirmed or denied one of another; whence we may take notice, that general certainty is never to

1

be found but in our ideas. Whenever we go to feek it elsewhere in experiment, or obfervations without us, our knowledge goes not beyond particulars. It is the contemplation of our own abstract ideas that alone is able to afford us general knowledge.

CHAP. VII.

TH

OF MAXIMS.

$1. They are felf-evident.

HERE are a fort of propofitions, which under the name of maxims and axioms have paffed for principles of science; and because they are felf-evident, have been supposed innate, although nobody (that I know) ever went about to show the reafon and foundation of their clearness or cogency. It may however be worth while to inquire into the reafon of their evidence, and fee whether it be peculiar to them alone, and alfo examine how far they influence and govern our other knowledge.

§ 2. Wherein that Self-evidence confifts. KNOWLEDGE, as has been shown, confifts in the perception of the agreement or difagreement of ideas : Now where that agreement or difagreement is perceived immediately by itself, without the intervention or help of any other, there our knowledge is felf-evident. This will appear to be fo to any one who will but confider any of thofe propofitions, which, without any proof, he affents to at firft fight; for in all of them he will find, that the reafon of his affent is from that agreement or difagreement which the mind, by an immediate comparing them, finds in thofe ideas anfwering the affirmation or negation. in the propofition.

3. Self-evidence not peculiar to received Axioms. THIS being fo, in the next place let us confider, whether this felf-evidence be peculiar only to those propofitions, which commonly pafs under the name of

maxims, and have the dignity of axioms allowed them. And here it is plain, that feveral other truths, not allowed to be axioms, partake equally with them in this felf-evidence. This we fhall fee, if we go over thefe feveral forts of agreement or difugreement of ideas, which I have above mentioned, viz. identity relation, co-existence, and real exiltence; which will difcover to us, that not only thofe few propofitions, which have had the credit of maxims, are self-evident, but a great many, even almoft an infinite num. ber of other propofitions, are fuch."

§4. 1. As to Lentity and Diversity, all Propofitions are equally felf-evident."

FOR, firft, the immediate perception of the agreement or difagreement of identity being founded in the mind's having distinct ideas, this affords us as many felf-evia dent propofitions as we have diftin&t ideas. Every one that has any knowledge at all, has, as the foundation of it, various and diftinct ideas; and it is the first act of the mind (without which it can never be capable of any knowledge) to know every one of its ideas by itfelf, and diftinguish it from others. Every one finds in himself, that he knows the ideas he has; that he knows alfo, when any one is in his understanding, and what it is; and that when more than one are there, he knows them diftinctly and unconfufedly one from another; which always being fo (it being impoffible but that he fhould perceive what he perceives), he can never be in doubt when any idea is in his mind, that it is there, and is that idea it is; and that two distinct ideas, when they are in his mind, are there, and are not one and the fame idea. So that all fuch affirmations and negations are made without any poffibility of doubt, uncertainty or he fitation, and muft neceffarily be affented to as foon as understood; that is, as foon as we have in our minds determined ideas, which the terms in the propofition ftand for; and therefore wherever the mind with attention confiders any propofition, fo as to perceive the two ideas fignified by the terms, and affirm

ed or denied one of the other, to be the fame or different; it is prefently and infallibly certain of the truth of fuch a propofition, and this equally, whether thefe propofitions be in terms ftanding for more general ideas, or fuch as are lefs fo, v. g. whether the general idea of being be affirmed of itfelf, as in this propofition, whatsoever is, is; or a more particular ida be affirmed of itself, as a man is a man, or whatfoever is white, is white; or whether the idea of being in general be denied of not being, which is the only (if I may fo call it) idea different from it, as in this other propofition, it is impoffible for the fame thing to be, and not to be; or any idea of any particular being be denied of another different from it, as a man is not a barfe, red is not blue. The difference of the ideas, as foon as the terms are understood, makes the truth of the propofition prefently vifible, and that with an equal certainty and eafinefs in the lefs, as well as the more general propofitions, and all for the fame reason, viz. because the mind perceives in any ideas, that it has the fame idea to the fame with itfelf; and two different ideas to be different, and not the fame; and this it is equally certain of, whether thefe ideas be more or less general, abftract and comprehenfive. . It is not therefore alone to thefe two general propofitions, whatsoever is, is; and, it is impoffible for the fame thing to be, and not to be; that this felf-evidence blongs by any peculiar right. The perception of being, or not being, belongs no more to these vague ideas, fignified by the terms whatsoever and thing, than it does, to any other ideas; these two general maxims amounting to no more, in thort, but this, that the fame is the fame, and fame is not different, are truths known in more particular inftances, as well as in thefe general maxims, and known alfo in particular inftances, before thefe general maxims are ever thought on, and draw all their force from the difcernment of the mind employed about particular ideas. There is nothing more visible than that the mind, without the help of any proof, or reflection on either of these general pro-

Book IV. pofitions, perceives fo clearly, and knows fo certainly, that the idea of white is the idea of white, and not the idea of blue; and that the idea of white, when it is in the mind, is there, and is not abfent; that the confideration of thefe axioms can add nothing to the evidence or certainty of its knowledge. Just fo it is (as every one may experiment in himself) in all the ideas a man has in his mind: He knows each to be itfelf, and not to be another; and to be in his mind, and not away when it is there, with a certainty that cannot be greater; and therefore the truth of no general propofition can be known with a greater certainty, nor add any thing to this. So that in refpect of i» dentity, our intuitive knowledge teaches as far as our ideas; and we are capable of making as many felfevident propofitions, as we have names for diftinct ideas. And I appeal to every one's own mind, whether this propofition, a circle is a circle, be not as felfevident a propofition, as that confifting of more ge neral terms, whatfoever is, is: And again, whether this propofition, blue is not red, be not a propofition that the mind can no more doubt of, as foon as it unftands the words, than it does of that axiom, it is impoffible for the fame thing to be, and not to be and fo of all the like.

§ 5. 2. In Co-existence we have few felf-evidens Propofitions.

SECONDLY, As to co, existence, or fuch neceffary connection between two ideas, that in the subject where one of them is fuppofed, there the other must neceffarily be alfo Of fuch agreement or difagreement as this, the mind has an immediate perception but in very few of them, and therefore in this fort we have but very little intuitive knowledge; nor are there to be found very many propofitions that are felf-evident, though fome there are, v. g. the idea of filling a place equal to the contents of its fuperficies, being ar nexed to our idea of body, I think it is a felf evident propofition, that two bodies cannot be in the fame place,