reason place this, and some other such maxims, at the entrance of their systems; that their scholars, having in the beginning perfectly acquainted their thoughts with these propositions, made in such general terms, may be used to make such reflections, and have these more general propositions, as formed rules and sayings, ready to apply to all particular cases. Not that if they be equally weighed, they are more clear and evident than the particular instances they are brought to confirm; but that, being more familiar to the mind, the very naming them is enough to satisfy the understanding. But this, I say, is more from our custom of using them, and the establishment they have got in our minds, by our often thinking of them, than from the different evidence of the things. But before custom has settled methods of thinking and reasoning in our minds, I am apt to imagine it is quite otherwise; and that the child, when part of his apple is taken away, knows it better in that particular instance, than by this general proposition, the whole is equal to all its parts; and that if one of these have need to be confirmed to him by the other, the general has more need to be let into his mind by the particular, than the particular by the general. For in particulars our knowledge begins, and so spreads itself by degrees to generals. Though afterwards the mind takes the quite contrary course, and having drawn its knowledge into as general propositions as it can, makes those familiar to its thoughts, and accustoms itself to have recourse to them, as to the standards of truth and falsehood. By which familiar use of them, as rules to measure the truth of other propositions, it comes in time to be thought, that more particular propositions have their truth and evidence from their conformity to these more general ones, which in discourse and argumentation are so frequently urged, and constantly admitted. And this I think to be the reason why amongst so many self-evident propositions, the most general only have had the title of maxims.

f. 12. Maxims, if care be not taken in the use of words, may, prove contradictions.

One thing farther, I think, it may not be amiss to observe concerning these general maxims, that they are so far from improving or establishing our minds in true knowledge, that if our notions be wrong, loose or unsteady, and we resign up our thoughts to the sound of words, rather

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than fix them on settled determined ideas of things; I say, these general maxims will serve to confirm us in mistakes; and in such a way of use of words, which is most common, will serve to prove contradictions: v. g. he that, with Des Cartes, shall frame in his mind an idea of what he calls body to be nothing but extension, may easily demonstrate that there is no vacuum, z. e. no space void of body, by this maxim, what is, is. For the idea to which he annexes the name body, being bare extension, his knowledge, that space cannot be without body, is certain. For he knows his own idea of extension clearly and distinctly, and knows that it is what it is, and not another idea, though it be called by these three names, extension, body, space. Which three words, standing for one and the same idea, may no doubt, with the same evidence and certainty, be affirmed one of another, as each of itself; and it is as certain, that whilst I use them all to stand for one and the same idea, this predication is as true and identical in its signification, that space is body, as this predication is true and identical, that body is body, both in signification and sound.

§. 13. Instance in vacuum.

But if another should come, and make to himself another idea, different from Des Cartes's, of the same thing, which yet with Des Cartes, he calls by the same name body; and make his idea, which he expresses by the word hody, to be of a thing that hath both extension and solidity together; he will as easily demonstrate, that there may be a vacuum, or space without a body, as Des Cartes demonstrated the contrary. Because the idea to which he gives the name space being barely the simple one of extension; and the idea to which he gives the name body, being the complex idea of extension and resistibility, or solidity, together in the same subject; these two ideas are not exactly one and the same, but in the understanding as distinct as the ideas of one and two, white and black, or as of corporeity and humanity, if I may use those barbarous terms: and therefore the predication of them in our minds, or in. words standing for them, is not identical, but the negation of them one of another, viz. this proposition, extension or space is not body, is as true and evidently certain, as this maxim, it is impossible for the same thing to be, and not to be, can make any proposition.

§. 14. They prove not the existence of things without us. But yet though both these propositions (as you see) may

be equally demonstrated, viz. that there may be a vacuum, and that there cannot be a vacuum, by these two certain principles, viz. what is, is; and the same thing cannot be and not be yet neither of these principles will serve to prove to us, that any, or what bodies do exist; for that we are left to our senses, to discover to us as far as they can. Those universal and self-evident principles, being only our constant, clear, and distinct knowledge of our own ideas, more general or comprehensive, can assure us of nothing that passes without the mind; their certainty is founded only upon the knowledge we have of each idea by itself, and of its distinction from others; about which we cannot be mistaken whilst they are in our minds, though we may, and often are mistaken when we retain the names without the ideas; or use them confusedly sometimes for one, and sometimes for another idea, In which cases the force of these axioms, reaching only to the sound, and not the signification of the words, serves only to lead us into confusion, mistake and error. It is to show men, that these maxims, however cried up for the great guards of truth, will not secure them from error in a careless loose use of their words, that I have made this remark. In all that is here suggested concerning their little use for the improvement of knowledge, or dangerous use in undetermined ideas, I have been far enough from saying or intending they should be laid aside, as some have been too forward to charge me. I affirm them to be truths, self-evident truths; and so cannot be laid aside. As far as their influence will reach, it is in vain to endeavour, nor will I attempt to abridge it. But yet, without any injury to truth or knowledge, I may have reason to think their use is not answerable to the great stress which seems to be laid on them; and I may warn men not to make an ill use of them, for the confirming themselves in errors.

§. 15. Their application dangerous about complex ideas.

But let them be of what use they will in verbal propositions, they cannot discover or prove to us the least knowledge of the nature of substances, as they are found and exist without us, any farther than grounded on experience. And though the consequence of these two propositions, called principles, be very clear, and their use not dangerous or hurtful, in the probation of such things,

wherein there is no need at all of them for proof, “but such as are clear by themselves without them, viz. where our ideas are determined, and known by the names that stand for them yet when these principles, viz. what is, is; and it is impossible for the same thing to be, and not to be; are made use of in the probation of propositions, wherein are words standing for complex ideas; v. g. man, horse, gold, virtue; there they are of infinite danger, and most commmonly make men receive and retain falsehood for manifest truth, and uncertainty for demonstration upon which follow error, obstinacy, and all the mischiefs that can happen, from wrong reasoning. The reason whereof is not, that these principles are less true, or of less force in proving propositions made of terms standing for complex ideas, than where the propositions are about simple ideas. But because men mistake generally, thinking that where the same terms are preserved, the propositions are about the same things, though the ideas they stand for are in truth different; therefore these maxims are made use of to support those, which in sound and appearance are contradictory propositions; as is clear in the demonstrations above mentioned about a vacuum.So that whilst men take words for things, as usually they do, these maxims may and do commonly serve to prove contradictory propositions: as shall yet be farther made manifest.

f. 16. Instance in man.

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For instance, let man be that concerning which you would by these first principles demonstrate any thing, and we shall see, that so far as demonstration is by these principles, it is only verbal, and gives us no certain universal true proposition, or knowledge of any being existing without us. First, a child having framed the idea of a man, it is probable that his idea is just like that picture, which the painter makes of the visible appearances joined together; and such a complication of ideas together in his understanding, makes up the simple complex idea, which he calls man, whereof white or flesh colour in England being one, the child can demonstrate to you that a negro is not a man, because white colour was one of the constant simple ideas of the complex idea he calls man; and therefore he can demonstrate by the principle it is impossible for the same thing to be, and not to be, that a negro is not a man; the foundation of his certainty being not

that universal proposition, which perhaps he never heard nor thought of, but the clear distinct perception he hath of his own simple ideas of black and white, which he cannot be persuaded to take, nor can ever mistake one for another, whether he knows that maxim or no: and to this child, or any one who hath such an idea, which he calls man, can you never demonstrate that a man bath a soul, because his idea of man includes no such notion or idea in it. And therefore to him, the principle of what is, is, proves not this matter; but it depends upon collection and observation, by which he is to make his complex idea called man.

§. 17.

Secondly, another that hath gone farther in framing and collecting the idea he calls man, and to the outward shape adds laughter and rational discourse, may demonstrate that infants and changelings are no men, by this maxim, it is impossible for the same thing to be, and not to be; and I have discoursed with very rational men, who have actually denied that they are men.

6. 18.

Thirdly, perhaps another makes up the complex idea which he calls man, only out of the ideas of body in general, and the powers of language and reason, and leaves out the shape wholly: this man is able to demonstrate, that a man may have no hands, but be quadrupes, neither of those being included in his idea of man; and in whatever body or shape he found speech and reason joined, that was a man; because having a clear knowledge of such a complex idea, it is certain that what is, is.

§. 19. Little use of these maxims in proofs where we have clear and distinct ideas.

So that, if rightly considered, I think we may say, that where our ideas are determined in our minds, and have annexed to them by us known and steady names under those settled determinations, there is little need or no use at all of these maxims, to prove the agreement or disagreement of any of them. He that cannot discern the truth or falsehood of such propositions, without the help of these and the like maxims, will not be helped by these maximus to do it: since he cannot be supposed to know the truth of these maxims themselves without proof, if he cannot know the truth of others without proof, which are as self-evident