The ancient Philofophers granted, that all knowledge mufl be grounded on firfl princi- ples, and that there is no reafoning without them. The Peripatetic philofophy was redun- dant rather than deficient in firfl: principles. Perhaps the abufe of them in that ancient fyf- tem may have brought them into difcredit in modern times; for as the befl things may be abufed, fo that abufe is apt to give a difgufl to the thing itfeif; and as one extreme often leads into the oppofite, this feems to have been the cafe in the refpeft paid to firfl principles in an- cient and in modern times.
Des Of FIRST PRINCIPLES in GENERAL. 241 Des Cartes thought one principle, expref-C HAP. fed in one word cogito, a fufficient foundation ^^,..^„.^ for his whole fyflem, and alked no more.
Mr. Locke feems to think firfl principles of very fmall ufe. Knowledge confiding, ac- cording to him, in the perception of the agree- ment or difagreement of our ideas; when we have clear ideas, and are able to compare them together, we may always fabricate firfl princi- ples as often as we have occafion for them. Such differences we find among Philofophers about firfl principles.
It is likewife a queflioli of fome moment, whether the differences among m.en about firfl: principles can be brought to any iflue? When, in difputes, one man maintains that to be a firfl principle, which another denies, common- ly both parties appeal to common fenfe, and fo the matter refls; Now, is there no way of difcuffmg this appeal? Is there no mark or criterion, whereby firfl principles that are tru- ly fuch, may be diflinguifhed from thofe that affume the charafter without a jufl title? I (hall humbly offer in the following propofitions what appears to me to be agreeable to truth in thefe matters, always ready to change my opi- nion upon convidion.
I. Firji, I hold it to be certain, and even demonflrable. That all knowledge got by rea-- foning mufl be built upon firfl principles.
This is as certain as that every houfe mufl; have a foundation. The power of reafoning, in this refpect, refembles the mechanical pow- ers or engines; it mufl: have a fixed point to refl: upon, otherwife it fpends its force in the air, and produces no effect.
Vol. IL R When € H A P. When we examine, in the way of analyi%y "• the evidence of any pFopofiticn, either we find ^•^^^1^ it felf-evident, or it reds upon one or more propcfitions that fupport it. The fame thing may be faid of the propofitions that fupport it; and of thofe that fupport them, as far back as we can go. But we cannot go back in this track to infinity. Where then mufi: this ana- lyfis ftop? It is evident that it mufl flop only when we come to propofitions, which fupport all that are built upon them, but are themfelves fupported by none, that is, to felf-evident pro- pofitions.
Let us again confider a fynthetical proof of any kind, where we begin with the premifes, and purfue a train of confequences, until we come to the lad conclufion, or thing to be proved. Here we mufl begin, either with felf-evident propofitions, or with fuch as have been already proved. When the lafl is the cafe, theproof of the propofitions, thus afTumed, is a part of our proof; and the proof is defici- ent without it. Suppofe then the deficiency fupplied, and the proof completed, is it not evident that it mufl fet out with felf-evident propofitions, and that the whole evidence mufl refl upon them? So that it appears to be de» monflrable that, without firfl principles, ana- lytical reafoning could have no end, and fyn- thetical reafoning could have no beginning; and that every conclufion got by reafoning mufl refl with its whole weight upon firfi prin- ciples, as the building does upon its founda- tion.
2. A fecond propofition is. That fome firfl principles yield conclufions that are certain, others Of FIRST PRINCIPLES in GENERAL. 243 others fuch as are probable, in various de- C H A P. grees, from the higheft probabiHty to the low- ^^' eft.
In juft reafoning, the ftrength or wcaknefs of the conclufion will always correfpond to that of the principles on which it is grriunded.
In a matter of teftimony, it is felf-evident, that the teftimony of two is better than that of one, fuppofing them equal in character, and in their means of knowledge; yet the fimple teftimony may be true, and that which is pre- ferred to it may be falfe.
When an experiment has fucceeded in fe- veral trials, and the circumftances have been marked with care, there is a felf-evident pro- bability of its fucceeding in a new trial; but there is no certainty. The probabihty, in fome cafes, is much greater than in others; becaufe, in fome cafes, it is much eafier to obferve all the circumftances that may have influence upon the event than in others. And it is poffible, that, after many experiments made with care, our expeftation may be fruf- trated in a fucceeding one, by the variation of fome circumftance that has not, or perhaps could not be obferved.
Sir Isaac Newton has laid it down as a firft principle in natural philofophy, that a property which has been found in all bodies upon which we have had accefs to make expe- riments, and which has always been found in its quantity to be in exact proportion to the quantity of matter in every body, is to be held as an univerfal property of matter.
This principle, as far as I know, has never been called in queftion. The evidence we have, that all matter is divifible, moveable, R 2 folid.
CHAP.folId, and inert, Is refolveable into this prln-- ^^^^^ ciple; and if it be not true, we cannot have ^'^^^^ any rational convidion that all matter has thofs properties. From the fame principle that great man has fhewn, that we have reafon to con- clude, that all bodies gravitate towards each other.
This principle, however, has not that kind of evidence which mathematical axioms have. It is not a neceflary truth whofe contrary is impoffible; nor did Sir Isaac ever conceive it to be fuch. And if it ihould ever be found, by juit experiments, that there is any part in- the compofition of fome bodies which has not gravity, the facl, if duly afcertained, muft be admitted as an exception to the general law of gravitation.
In games of chance, it is a firfl: principle, that every fide of a die has an equal chance to be turned up; and that, in a lottery, every ticket has an equal chance of being drawn out. From fuch firfl principles as thefe, which are the befl we can have in fuch matters, we may deduce, by demonftrative reafoning, the pre- cife degree of probability of every event in fuch games.
But the principles of all this accurate and profound reafoning can never yield a certain conclufion, it being impofTible to fupply a de- feft in the firfl principles by any accuracy in the reafoning that is grounded upon them. As water, by its gravity, can rife no higher in its courfe than the fountain, however artfully it be conduded; fo no conclufion of reafoning can have a greater degree of evidence than the Brft principles from which it is drawn.
From 0/ FIRST PRINCIPLES in GENERAL. 245 From thefe inftances, it is evident, that as C H A. p. there are fome firft principles that yield con- ^^• clufions of abfolutc certainty; fo there are ^— "v*^ others that can only yield probable conclufions; and that the lowefl degree of probability muft be grounded on firft principles as well as abfo- lute certainty.
3. A third proportion is, that it would con- tribute greatly to the ftability of human know- ledge, and confequently to the improvement of it, if the firft principles upon which the va- rious parts of it are grounded were pointed out and ascertained.
We have ground to think fo, both from facts, and from the nature of the thing.
Thei*e are two branches of human know- ledge in which this method has been followed, to wit, mathematics and natural philofophy; in mathematics, as far as we have books. It is in this fcience only, that, for more than two thoufand years fmce it began to be cultivated, we find no feds, no contrary fyftems, and hardly any difputes; or, if there have been dif- putes, they have ended as foon as the animo- lity of parties fubfided, and have never been again revived. The fcience, once firmly efta- blilhed upon the foundation of a few axioms and definitions, as upon a rock, has grown from age to age, fo as to become the loftieft and the moft folid fabric that human reafon can boaft.
Natural philofophy, till lefs than two hun- dred years ago, remained in the fame flu<5tua- ting ftate with the other fcience s. Every new fyftem pulled up the old by the roots. The fyftem builders, indeed, were always willing to accept of the aid of firft principles, when tthey were of their fide; but finding them infufficient CHAP, fufficlent to fiipport the fabric which their ima-t 1.g ^nation had raifed, they were only brought in 'as auxiUaries, and lo intermixed with conjec- tures, and with larne indudions, that their fyf- tems were hke Nebuchadnezzar's image, •whofe feet were partly of iron and partly of clay.
Lord Bacon firft delineated the only folid foundation on which natural philofophy can be built; and S'v Isaac Newton reduced the pi-incipi,e$ laid down by Bacon into three or four axioms, which he calls regula philofophan- di. Fro in thefe, together with the phasnome- na obferved by the fenfes, which he likewife lays down as firil principles, he deduces, by Itrift reafoning, the propofitions contained in the third book of his Principia, and in his Optics; and by this means has raifed a fabric in thofe two branches of natural philofophy, which is not liable to be Ihaken by doubtfui diiputation, but Hands immoveable upon the bafis of felf-evident principles.
This fabric has been carried on by the ac- ceffion of new difcoveries y but is no more ibject to revolutions.
i'he difputes about materia prima^ fubftantial forms, Nature's abhorring a vacuum, and bo- dies having no gravitation in their proper place, are now no more. The builders in this work are not put to the neceffity of holding a weapon in one hand while they build with the other: their whole employment is to carry on the work.
Yet it feems to be very probable, that if na«» tural philofophy had not been reared upon this folid foundation of felf-evident principles, it would have been to this day a field of battle, wherein Of FIRST PRINCIPLES in GENERAL. 247 wherein every inch of ground would have been ^ HA P. difputed, and nothing fixed and determined. '.
I acknowledge that mathematics and natural philolbphy, efpecially the former, have this ad- vantao;e of mod other fciences, that it is lefs difficult to form diftinft and determmate con- ceptions of the objefts about which they are employed; but as this difficulty is not infu'pe- rable, it affords a good reafon, indeed, why other fciences fhould have a longer infancy; but no reafon at all why they may not at lafl arrive at maturity, by the fame fleps as thofe of quicker growth.
The fafts I have mentioned may therefore lead us to conclude, that if in other branches of philofophy the firfl principles were laid, down, as has been done in mathematics and natural philofophy, and the fubfequent con- clufions grounded upon them, this would make it much more eafy to diftinguifh what is folid and well fupported from the vain fidions of human fancy.
But laying afide fads, the nature of the thing leads to the fame conclufion.
For when any fyflem is grounded upon firfl principles, and deduced regularly from them, we have a thread to lead us through the laby- rinth. The judgment has a diftinft and deter- minate objed:. The heterogeneous parts being feparated, can be examined each by itfelf.
The whole fyflem is reduced to axioms, de- finitions, and dedudions. Thefe are materials of very different nature, and to be meafured by a very different flandard; and it is much more eafy to judge of each, taken by itfelf, than to judge of a mafs wherein they are knead- ed together without diflindion. Let us con- lider how we judge of each of them.
Firji^ As to definitions, the matter is very eafy. They relate only to words, and differ- ences about them may produce different ways of fpeaking, but can never produce different ways of thinking, while every man keeps to his own definitions.
But as there is not a more plentiful fource of fallacies in reafoning than mens ufing the fame word fometimes in one fenfe and at other times in another, the beft means of preventing fuch fallacies, or of detecting them when they are committed, is definitions of words as accurate as can be given.
Secondly, As to dedudiofts drawn from prin- ciples granted on both fides, I do not fee how they can long be a matter of difpute among men who are not blinded by prejudice or partia- lity: For the rules of reafoning by which in- ferences may be drawn from premifes have been for two thoufand years fixed with great unanimity. No man pretends to difpute the rules of reafoning laid down by Aristotle, and repeated by every writer in dialeftics.
And we may obferve by the way, that the reafon why Logicians have been fo unanimous in determining the rules of reafoning, from Aristotle down to this day, feems to be, that they were by that great genius raifed, in a fciemific manner, from a few definitions and axioms. It may farther be obferved, that when men differ about a dedu£lion, whether it follows from certain premifes, this I think is aKvays owing to their differing about fome firft principle. 1 fhall explain this by an example.
Suppofe that, from a thing having begun to exift, one man infers that it mufl have had a caufe J another man does not admit the infer- ence-.
Of FIRST PRINCIPLES in GENERAL. 249 ence. Here It is evident, that the firfl takes CHAP, it for a lelf-evident principle, that every thing which begins to exift muft have a caufe. The other does not allow this to be felf-evident. Let them fettle this point, and the difpute will be at an end.
Thus I think it appears, that in rnatters of fcience, if the terms be properly explained, the firft principles upon which the reafoning is grounded be laid down and expofed to exami- nation, and the conclufions regularly deduced from them, it might be expeded, that men of candour and capacity, who love truth, and have patience to examine things coolly, might come to unanimity with regard to the force of the deduftions, and that their differences might be reduced to thofe they may have about firft principles.
4. K fourth propofitlon is, that Nature hath not left us deflitute of means whereby the can- did and honefl part of mankind may be brought to unanimity when they happen to differ about firfl principles.
When men differ about things that are taken to be firft principles or felf-evident truths, rea- foning feems to be at an end. Each party ap- peals to common fenfe. When one man^s common fenfe gives one determination, ano- ther man's a contrary determination, there feems to be no remedy but to leave every man to enjoy his own opinion. This is a common obfervation, and I believe a jufl one, if it be rightly underftood.
It is in vain to reafon with a man who denies the firft principles on which the reafoning is grounded. Thus, it would be In vain to at- tempt the proof of a propofitlon in Euclid to a man ^^'^P-a man who denies the axioms. Indeed, we ■ ought never to reafon with men who deny firfl principles from obftinacy and unwillingnefs to yield to reafon.
But is it not poiTible, that men who really love truth, and are open to conviction, may differ about firfl principles?
I think it is poffible, and that it cannot, without great v/ant of charity, be denied to be pofTible.
When this happens, every man who believes that there is a real diflinction between truth and error, and that the faculties which God has given us are not in their nature fallacious, mufl be convinced that there is a defed:, or a perverfion of judgment on the one fide or the other.
A man of candour and humility will, in fuch a cafe, very naturally fufpect his own judgment, fo far as to be defirous to enter into a ferious examination, even of what he has long held as a firfl principle. He will think it not impoffible, that although his heart be upright, his judgment may have been pervert- ed, by education, by authority, by party zeal, or by fome other of the common caufes of error, from the influence of which neither parts nor integrity exempt the human under^ Handing.
In fuch a date of mind, fo amiable, and fo becoming every good man, has Nature left him deflitute of any rational means by which he may be enabled, either to corredl his judg- ment if it be wrong, or to confirm it if it be right?
I hope it is not fo. I hope that, by the means which Nature has furnifhed, controverfies ©/FIRST PRINCIPLES In GENERAL. 251* fies about firfl; principles may be brought to an C H A P. iflue, and that the real lovers of truth may -^• come to unanimity v,'ith regard to them. ' ^ It is true, that, in other controverfie$, the procefs by which the truth of a propofitlon is difcovered, or its falfehood detecled, is by Ihevving its necelTary connedion with firfl prin- ciples, or its repugnancy to them. It is true, iikewife, that when tlie controverfy is, whether a proportion be itfelf a firfl principle, this pro- cefs cannot be applied. The truth, therefore, in controverfies of this kind, labours under a peculiar difadvantage. But it has advantages of another kind to compenfate this.
I. For, in the Jir/i place, in fuch contro- verfies, every man is a competent judge; and therefore it is difficult to impofe upon man- kind.
To judge of firfl principles, requires no more than a found mind free from prejudice, and a diflinO: conception of the queflion. The learned and the unlearned, the Philofopher and the day-labourer, are upon a level, and will pafs the fame judgment, when they are not milled by fome bias, or taught to renounce their underflanding from fome miilaken reli- gious principle.
In matters beyond the reach of common un- derflanding, the many are led by the few, and wiUingly yield to their authority. But, in matters of common fenfe, the few mufl yield to the many, when local and temporary pre- judices are removed. No man is now moved by the fubtile arguments of Zeno againfl mo- tion, though perhaps he knows not how to an- fwer them.
The ESSAY vr.
CHAP. The ancient fceptlcal fyftem furnlflies a re- '^' markable inflance of this truth. That fyftem, ^-"^^^^^ of which Pyrrho was reputed the father, was carried down, through a fucceffion of ages, by very able and acute Philofophers, who taught men to beUeve nothing at all, and elteemed it the higheft pitch of human wifdom to with-hold aflent from every propofition whatfoever. It was fupported with very great fubtilty and learning, as we fee from the wri- tings of Sextus Empiricus, the only author of that fe£l w^hofe writings have come down to our age. The affault of the Sceptics againft all fcience feems to have been managed with more art and addrefs than the defence of the Dogmatifts.
Yet, as this fyftem was an infult upon the common fenfe of mankind, it died away of it- IJelf; and it would be in vain to attempt to re- vive it. The modern fcepticifm is very differ- ent from the ancient, otherwife it would not have been allowed a hearing; and, when it has loll the grace of novelty, it will die away alfo, though it fhould never be refuted.
The modern fcepticifm, I mean that of Mr. KuME, is built upon principles which were very generally maintained by Philofophers, though they did not fee that they led to fcepti- cifm. Mr. Hume, by tracing, with great acutenefs and ingenuity, the confequences of principles commonly received, has Ihewn that they overturn all knowledge, and at laft over- turn themfelves, and leave the mind in perfect fufpenfe.
2. Secondly, We may obferve, that opinions which contradict firft principles are diftinguifh- ed from other errors by this; that they are not cnly falfe, but abfurd: And, to difcountenance abfurdityj Of FIRST PRINCIPLES in GENERAL. 253 abfurdity. Nature hath given us a particularC H A PJ" emotion, to wit, that of ridicuie, which feems ^^• intended for this very purpofe of putting out '~" '^ of countenance what is abfurd, either in opi- nion or pra6lice.
This weapon, when properly applied, cuts with as keen an edge as argument. Nature hath furnifhed us with the firfl to expofe ab- furdity; as with the lafl to refute error. Both are well fitted for their feveral offices, and are equally friendly to truth when properly ufed.
Both may be abufed to ferve the caufe of error: But the fame degree of judgment, which ferves to deteft the abufe of argument in falfe reafoning, ferves to dete6l the abufe of ridicule when it is wrong dire6ted.
Some have from nature a happier talent for ridicule than others; and the fame thing holds with regard to the talent of reafoning. Indeed, I conceive there is hardly any abfurdity, which, when touched with the pencil of a Lucian, at Swift, or a Voltaire, would not be put out of countenance, when there is not fome religi- ous panic, or very powerful prejudice, to blind the underftanding.
But it mufl be acknowledged, that the emo- tion of ridicule, even when mod natural, may be ftifled by an emotion of a contrary nature, and cannot operate till that is removed.
Thus, if the notion of fanftity is annexed to an objeft, it is no longer a laughable matter; and this vifor mud be pulled oft' before it ap- pears ridiculous. Hence we fee, that notions which appear mofh ridiculous to all who con- fider them coolly and indifferently, have no fuch appearance to thofe who never thought of them, but under the impreffion of religious awe and dread.
Even Even CHAP. Even where religion is not concerned, the ^^ ^ novelty of an opinion to thofe who are too fond of novelties; the gravity and folemnity with which it is introduced; the opinion we have entertained of the author; its apparent con- nection with principles already embraced, or fubferviency to interefts which we have at heart; and, above allj its being fixed in our minds at that time of life when we receive im- plicitly what we are taught; may cover its ab- furdity, and fafcinate the underflanding for a time.
But if ever we are able to view it naked, and dripped of thofe adventitious circumftan* ces from which it borrowed its importance and authority, the natural emotion of ridicule will exert its force. An abfurdity can be enter- tained by men of fenfe no longer than it w'ears a maik. When any man is found who has the (kill or the boldnels to pull off the ma(k, it can no longer bear the light; it llinks into dark corners for a while, and then is no more heard of, but as an objed of ridicule.
Thus I conceive, that firli: principles, which are really the diftates of common fenfe, and directly cppofed to abfurdities in opinion, will always, froui the conflitution of human na- ture, fupport themfelves, and gain rather than lofe ground smong mankind.
3. Thirdly, It may be obferved, that al- though it is contrary to the nature of firft principles to admit of diredt or apodidical proof; yet there are certain v. ays cf reafoning even about them, by w^hich thofe thrtt are juft and folid may be confirmed, and thofe that are falfe may be detected. It may here be proper to Of FIRST PRINCIPLES in GENERAL. 255 to mention fomc of the topics from which we ^ ^^ ^* may reafon in matters of this kind. ^ "^ Firji, It is a good argument ad bominem, if it can be (hewn, that a firft principle which a man rejects, (lands upon the fame footing with others v/hich he admits: For, when this is the cafe, he mufl: be guilty of an incon- fiftency who holds the one and rejeds the other.
Thus the faculties of confcioufnefs, of me- mory, of external fenfe, and of reafon, are all equally the gifts of Nature. No good rea- fon can be aihgned for receiving the teftimony of one of them, which is not of equal force with regard to the others. The greateft Scep- tics admit the teftimony of confcioufnefs, and allow, that what it teftifies is to be held as a firft principle. If therefore they rejeO: the immediate teftimony of fenfe, or of memory, they are guilty of an inconfiftency.
Secondly^ A firft principle may admit of a proof ad ahfurdum.
In this kind of proof, which is very common in mathematics, we fuppofe the contradictory proportion to be true. We trace the confe- quences of that fuppofition in a train of rea- foning; and if we find any of its neceifary confequences to be manifeftly abfurd, we con- clude the fuppofition from which it followed to be falfe j and therefore its contradi6tory to be true.
There is hardly any propofition efpecially of thofe that may claim the character of firft prin- ciples, that ftands alone and unconnefted- It draws many others along with it in a chain that cannot be broken. He that takes it up muft bear the burden of all its confequences; and and CHAP, and if that is too heavy for him to bear, he ■ muft not pretend to take it up. ^^^^^^"^ Thirdly^ 1 conceive, that the confent of ages and nations, of the learned and unlearned, ought to have great authority vi^ith regard to firft principles, where every man is a compe- tent judge.
Our ordinary conduft in life is built upon firft principles, as well as our fpeculations in philofophy; and every motive to adion fup- pofes fome belief. When we find a general agreement among men, in principles that con- cern human life, this mufl have great autho- rity with every fober mind that loves truth.
Tt is pleafant to obferve the fruitlefs pains which Bifhop Berkeley takes to fhew, that his fyftem of the non-exiftence of a material world did not contradidl the fentiments of the vulgar, but thofe only of the Philofophers.
With good reafon he dreaded more to op* pofe the authority of vulgar opinion in a mat- ter of this kind, than all the fchools of Philo- fophers* Here perhaps it will be faid. What has au- thority to do in matters of opinion? Is truth to be determined by moft votes? Or is autho- rity to be again raifed out of its grave to ty- rannife over mankind?
I am aware that, in this age, an advocate for authority has a very unfavourable plea; but I willi to give no more to authority than is its due.
Moft juftly do we honour the names of thofe benefadors to mankind who have contributed more or lefs to break the yoke of that autho- rity which deprives men of the natural, the unalienable right of judging for themfelves; but 0/ FIRST IPRINCIPLES in GENERAL. 557 but while we Indulge a jufl animofity againftC HAP. this authority, and againfl all who would fub- ^^• jed us to its tyranny, let us remember how ^"'"''''''^ comnlon the folly is, of going from one faulty extreme into the oppofite.
Authority, though a very tyrannical miflrefs to private judgment, may yet, on fome occa- fions, be a ufeful handmaid; this is all flie is entitled to, and this is all I plead in her behalf.
The juftice of this plea will appear by put- ting a cafe in a fcience, in which, of all fci- €nces, authority is acknowledged to have lead Weight.
Suppofe a Mathematician has made a difco-^ Very in that fcience which he thinks important 5 that he has put his demonftration in juft order; and, after examining it with an attentive eye, has found no flaw in it; I would afk, Will there not be ft ill in his breaft fome diffidence, fome jcaloufy leaft the ardour of invention may have made him overlook fome falfc ftep? This muft be granted.
He commits his demonftration to the exa- mination of a mathematical friend, whom he cfteems a competent judge, and waits v/ith im- patience the iflue of his judgment* Here I would alk again. Whether the verdid of his friend, according as it is favourable or un- favourable, will not greatly increafe or dimi- nifli his confidence in his own judgment t Moft certainly it will, and it ought.
If the judgment of his friend agree with his own, efpecially if it be confirmed by two or three able judges, he refts fecure of his difco- very without farther examination; but if it be unfavourable, he is brought back into a kind of fufpenfe, until the part that is fufpeded un- Vol. II« S dergoes CHAP, dergoes a new and a more rigorous exami- '"'^^ 1 hope what is fuppofed in this cafe is agree- able to nature, and to the experience of candid and modeft men on fuch occafions; yet here we fee a man's judgment, even in a mathema- tical demonftration, confcious of fome feeble- nefs in itfelf, feeking the aid of authority to fupport it, greatly flrengthened by that authori- ty, and hardly able to ftand eredt againft it, without fome new aid.
Society in judgment, of thofe who are ef- teemed fair and competent judges, has effects very fimilar to thofe of civil fociety; it gives flrength and courage to every individual; it removes that timidity which is as naturally the companion of folitary judgment, as of a foli- tary man in the ftate of nature.
Let us judge for ourfelves therefore, but let us not difdain to take that aid from the autho-*' rity of other competent judges, which a Ma- thematician thinks it necelfary to take in that fcience, which of all fciences has lead to do with authority.
In a matter of common fenfe, every man is no lefs a competent judge than a Mathemati- cian is in a mathematical demonftration; and there mud be a great prefumption that the judgment of mankind, in fuch a matter, is the natural ifl'ue of thofe faculties which God hath given them. Such a judgment can be erroneous only when there is fome caufe of the error, as general as the error is: When this can be ihewn to be the cafe, I acknowledge it ought to have its due weight. But to fuppofe a general deviation from truth among man- kind in things felf-evident, of which no caufe can be afligned, is highly unreafonable.
Perhaps 0/ FIRST PRINCIPLES in GENERAL. 259 Perhaps it may be thought impoffible to col-^ HAP. Ie6t the general opinion of men upon any point ^.,.^-^ whatfoever; and therefore, that this authority can ferve us in no (lead in examining firft principles. But I apprehend, that in many ca- fes this is neither impoffible nor difficult.
Who can doubt whether men have univer- fally believed the exiftence of a material world? Who can doubt whether men have univerfally believed, that every change that happens in nature mufh have a caufe? Who can doubt •whether men have univerfally believed, that there is a right and a wrong in human condudl; fome things that merit blame, and others that are entitled to approbation?
The univerfality of thefe opinions, and of many fuch that might be named, is fufficiently evident, from the whole tenor of human con- du£l;, as far as our acquaintance reaches, and from the hiftory of all ages and nations of which we have any records.
There are other opinions that appear to be iiniverfal, from what is common in the ftruc- ture of all languages.
Language is the exprefs image and picture bf human thoughts; and from the picture we may draw fome certain conclufions concerning the original; We find in all languages the fame parts of fpeech; we find nouns, fubftantive and ad- jective; verbs, adive and paffive, ill their va- rious tenfes, numbers, and moods. Some rules of fyntax are the fame in all languages.
Now what is common in the ftructure of languages, indicates an uniformity of opinion in thofe things upon which that ftrudure is grounded.
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