$ 12. 4. Because of wrong Principles. FOURTHLY, The mind, by preceeding upon false prin ciples, is often engaged in abfurdities and difficulties, brought into ftraits and contradictions, without knowing how to free itself; and in that case it is in vain to implore the help of reafon, unless it be to discover the falfehood, and reject the influence of thofe wrong principles. Reafon is fo far from clearing the difficulties which the building upon falfe foundations brings a man into, that if he will purfue it, it entangles him the more, and engages him deeper in perplexities.

$13. 5. Because of doubtful Terms.

FIFTHLI, As obfcure and imperfect ideas often involve our reafon, fo upon the fame ground, do dubious words and uncertain figns often in difcourfes and arguings, when not warily attended to, puzzle mas reafon, and bring them to a nonplus. But thefe two latter are our fault, and not the fault of reafon; but yet the confequences of them are nevertheless obvious, and the perplexities or errors they fill mens minds with are every where obfervable.

§ 14. Our higheft Degree of Knowledge is intuitive, without Reafening.

SOME of the ideas that are in the mind, are fo there, that they can be by themselves immediately compared one with another; and in these the mind is able to perceive that they agree or disagree as clearly as that it has them. Thus the mind perceives that an arch of a circle is lefs than the whole circle, as clearly as it does the idea of a circle; and this therefore, as has been said, I call intuitive knowledge, which is certain beyond all doubt, and needs no probation, nor can have any, this being the higheft of all human certainty. In this confifts the evidence of all those maxims, which nobody has any doubt about, but every man (does not, as is faid, only affent to, but) knows to be true, as foon as ever they are propofed to his understanding. In the discovery of and affent to these truths, there is no use of the difcurfive faculty, no need of reafoning, but they are known by a fupe

rior and higher degree of evidence. And fuch, if I may guefs at things unknown, I am apt to think that angels have now, and the fpirits of just men made perfect shall have, in a future ftate, of thousands of things, which now either wholly efcape our apprehenfions, or which, our fhort-fighted reafon having got fome faint glimpfe of, we in the dark grope

after.

15. The next is Demonftration by Reafoning. BUT though we have here and there a little of this clear light, fome fparks of bright knowledge, yet the greatest part of our ideas are fuch, that we cannot difcern their agreement or difagreement by an immediate comparing them; and in all these we have need of reafoning, and muft by difcourfe and inference make our discoveries. Now of these there are two forts, which I fhall take the liberty to mention here again.

Firft, Those whofe agreement or disagreement, though it cannot be feen by an immediate putting them together, yet may be examined by the intervention of other ideas which can be compared with them. In this cafe, when the agreement or difagreement of the intermediate idea on both fides, with those which we would compare, is plainly difcerned, there it amounts to demonftration, whereby knowledge is produced, which though it be certain, yet it is not fo eafy, nor altogether fo clear as intuitive knowledge; because in that there is barely one fimple intuition, wherein there is no room for any the leaft mistake or doubt; the truth is feen all perfectly at once. In demonstration, it is true, there is intuition too, but not altogether at once; for there must be a remembrance. of the intuition of the agreement of the medium, or intermediate idea, with that we compared it with before, when we compare it with the other; and where there be many mediums, there the danger of the miftake is the greater; for each agreement or difagreement of the ideas must be observed and feen in each ftep of the whole train, and retained in the memory jult as it is, and the mind must be fure that no part of

what is neceffary to make up the demonstration is omitted or overlooked. This makes fome demonstrations long and perplexed, and too hard for those who have not strength of parts diftinctly to perceive, and exactly carry fo many particulars orderly in their heads; and even those who are able to mafter fuch intricate fpeculations, are fain fometimes to go over them again, and there is need of more than one review before they can arrive at certainty. But yet where the mind clearly retains the intuition it had of the agreement of any idea with another, and that with a third, and that with a fourth, c. there the agree ment of the first and the fourth is a demonstration, and produces certain knowledge, which may be called ra. tional knowledge, as the other is intuitive.

§ 16. To fupply the Narrowness of this, we have nothing but Judgment upon probable reafoning. SECONDLY, there are other ideas whose agreement or disagreement can no otherwise be judged of but by the intervention of others, which have not a certain agreement with the extremes, but an ufual or likely one; and in thefe it is that the judgment is properly exercifed, which is the acquiefcing of the mind, that any ideas do agree, by comparing them with fuch probable mediums. This, though it never amounts to knowledge, no, not to that which is the lowest degree of it, yet fometimes the intermediate ideas tie the extremes fo firmly together, and the probability is fo clear and ftrong, that affent as neceffarily follows it, as knowledge does demonftration. The great excellency and ufe of the judgment is to obferve right, and take a true eftimate of the force and weight of each probability, and then cafting them up all right together, choose that fide which has the overbalance.

$ 17. Intuition, Demonftration, Judgment. INTUITIVE knowledge is the perception of the certain agreement or difagreement of two ideas immediately compared together.

Rational knowledge is the perception of the certain agreement or difagreement of any two ideas, by the intervention of one or more other ideas.

Judgment is the thinking or taking two ideas to agree or disagree, by the intervention of one or more ideas, whofe certain agreement or disagreement with them it does not perceive, but hath obferved.to be frequent and usual.

$18. Confequences of Words, and Confequences of

Ideas.

THOUGH the deducing one propofition from another, or making inferences in words, be a great part of reafon, and that which it is ufually employed about, yet the principal act of ratiocination is the finding the agreement or disagreement of two ideas one with another, by the intervention of a third; as a man by a yard finds two houses to be of the fame length, which could not be brought together to measure their equality by juxta-pofition. Words have their confequences, as the figns of fuch ideas; and things agree of difagree, as really they are; but we obferve it only by our ideas.

$ 19. Four Sorts of Arguments.

BEFORE we quit this fubject, it may be worth our while a little to reflect on four Jorts of arguments, that men in their reafonings with others do ordinarily make use of to prevail on their affent, or at least so to awe them as to filence their oppofition.

1. Ad Verecundiam.

First, The first is, to allege the opinions of men, whofe parts, learning, eminency, power, or fome other cause, has gained a name, and fettled their reputation in the common efteem with fome kind of authority. When men are established in any kind of dignity, it is thought a breach of modefty for others to derogate any way from it, and queftion the authority of men who are in poffeffion of it. This is apt to be cenfured, as carrying with it too much of pride, when a man does not readily yield to the determination of approved authors, which is wont to be re

ceived with refpect and fubmiffion by others; and it is looked upon as infolence for a man to fet up and adhere to his own opinion against the current stream of antiquity, or to put it in the balance against that of fome learned doctor, or otherwife approved writer. Whoever backs his tenets with fuch authorities, thinks he ought thereby to carry the caufe, and is ready to ftyle it impudence in any one who shall stand out against them. This I think may be called argumentum

ad verecundiam.

§ 20. 2. Ad Ignorantiam.

SECONDLY, Another way that men ordinarily ufe to drive others, and force them to fubmit their judg ments, and receive the opinion in debate, is to require the adverfary to admit what they allege as a proof, or to affign a better. And this I call argumentum ad ig

norantiam.

§ 21. 3. Ad Hominem. THIRDLY, A third way is to prefs a man with confe quences drawn from his own principles or conceffions. This is already : under the name of argumen

tum ad hominem.

$22. 4. Ad Judicium.

FOURTHLY, The fourth is the ufing of proofs drawa from any of the foundations of knowledge or probabi lity. This I call argumentum ad judicium. This alone of all the four brings true inftruction with it, and advances us in our way to knowledge. For, 1. It argues not another man's opinion to be right, because I out of refpect, or any other confideration but that of conviction, will not contradict him. 2. It proves not another man to be in the right way, nor that I ought to take the fame with him, because I know not a better. 3. Nor does it follow that another man is in the right way, because he has shown me that I am in the wrong. I may be modeft, and therefore not oppose another man's perfuafion; I may be ignorant, and not be able to produce a better; I may be in an error, and another may show me that I am fo; this may difpofe me, perhaps, for the reception of truth,

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