THIS then must be the Mode; two to two; the Authors, and the Pub­lishers; or rather we, I mean my fellow-Publisher and I, are onely as Lay-Brothers to the Principal Disputants Chry­saspis and Querela; and therefore no more can reasonably be expected of us, then to pre­sent their Papers, stand by, and look on; or at most, if occasion should afterwards require it, bear witness how they carried themselves: Nor let our lower condition discourage us; we may be honest as well as they; nay, per­haps with far more ease and security; their wisdoms still tempting them to be Polititi­ans, while our unskilfulness inclines us to plain dealing; a Quality, which my reason as well as interest, engages me to esteem, a­bove all the devices of the finest and craftyest wits.

[Page]First then I freely and openly acknow­ledge my self One, far highlyer oblig'd to Chrysaspis, (under another more fortunate Name) then to all the World besides, ha­ving continually receiv'd from Him so many and so happy satisfactions in the noblest and most important Inquisitions of a Rational Soul; yet seriously profess, I am not con­scious of ever following him one hairs bredth farther then his Reason drew me; and this, not onely by the humour of my nature (whether stubborn or ingenuous, I know not) that secures me from such a servile spirit; but by his express and constant direction, ne­ver to depend the least jot on him, but entirely on the pure force of Truth and Evidence: a Lesson I hope the Reader shall see I per­fectly observe in my frank relation of this Encounter; wherein▪ (if I may judge) they Both gave too much advantage to one ano­ther: for Chrysaspis's foot, which us'd to stand firm and strong, unhappily slipt; and Querela, instead of dispatching him, made at him with such a bungling blow, that him­self lay open to an easy revenge.

But, to disguise the story no longer in a Metaphor, Master White having written many excellent Pieces, both in Philosophy and Divinity, and endeavour'd (not with­out [Page] a good degree of Success) to reduce those noblest Sciences to a fair correspondence and orderly connexion, undertook to print a little Treatise in Geometry, hoping it might in­vite some apt to be affected with such mo­tives, to read his other works, not that they needed it, but we; nor is he so severely to be interpreted that the fate of all his Books should depend on this (God forbid so rich a treasure should be so rashly ventur'd) but conceiving he had found the Quadrature, he consequently argues; He has invented in Mathematicks what was thought impossible, therefore his other speculations are not to be neglected: which you would pervert to a quite contrary sense; He has miscarry'd in what was thought impossible, therefore he is deceiv'd in every thing else; which conse­quence if we admit, we are weak discour­sers; if we deny, 'tis a weak Discourse, ha­ving not the least reason to sustain it. 'Tis true, this his expectation met with the mis­chance of failing; but why should he not be allow'd the benefit of repenting? since, as soon as he saw his error, no lesse friendly then clearly discover'd to him by the Learn­ed and rightly Honourable Lord, my Lord Brouncker, he immediately retracted it, both by word, in his thankful Letters to his Lord­ship; [Page] and by deed, in his quick suppressing the Book when 'twas ready to be publish't, and what in so short a time could he have done more? who knowes how long Guldinus liv'd in a confidence of his error, before he retracted it? who knowes not how tenacious­ly all those famous Mathematicians that conceited they had found this Quadrature, cleav'd to their opinions? read but Guldi­nus himself, lib. 2. pro. 4. and you shall see how many he there brings in more glory­ing in the Invention, more obstinate in de­fending it, more dilatory in revoking it, then the so clamorously condemn'd Chrysaspis; yet every one mistaken as well as he: All I can say, is, 'tis the fate (alas!) of Circle-squares, and Philosopher-stone finders, to boast and to miscarry.

Instantly after this calling in Chrysaspis, out comes Querela, not onely disingenuous enough to bewray to the World the secret de­fects of Chrysaspis, after knowledg of its being recal'd; but bold enough to confess in print that knowledg; nay worse, envious e­nough to do all this in plain English, and a stile flat and mean, fit for the lowest capacity of the vulgar. Certainly, a proceeding nei­ther just nor civil; not to talk of courteous or charitable. But, Chrysaspis had wrong'd [Page] a friend of Querela's: and I willingly com­mend his undertaking to defend him, as one of the worthiest and most generous actions that belong to our nature; yet with this Cau­tion, he must take heed of injuring Reason, while he strives to do right to Friendship. Let's then examine the Cause.

Querela complains that Chrysaspis had stoln a thing cal'd (for really it was not) a Demonstration: the Accus'd answers the Charge, and gives his reasons to clear him­self. But, that they contend about being a plain error, in a Science where fallacies get neither credit nor profit, I can believe Chry­saspis may possibly fall into the same mistake with Guldinus (that was the friend's Name) but scarce can imagin he should steal from him a deaf nut, or a rotten apple: and therefore, since 'tis at least probable, the Casuist that allows so deep a revenge for ta­king away an Apple, meant a sound one, which no ways hinders my pretence; I desire this Case may be dismist for its under-value. You strive indeed to enhance the Crime, be­cause 'twas Guldinus's proper Invention, of which Chrysaspis rob'd him; and every one is apt to cherish, and tenderly love the issue of their own brain: But, what if it was no more then one of Guldinus's by blows? what [Page] if not so much, but a meer abortion? and therefore I desire again, it may be dismist; for an error ought never to be made much of, whoever is the father.

If it be said Chrysaspis suddenly took what he thought was sound; That would acquit him absolutely of even the least suspition to be conscious of Guldinus's Retractation, which is a greater Crime, and more severely imputed. Yet, that 'twas possible he might not know it, will easily be believ'd by any who know him: a Person soon weary of reading flourishes, and fine words, if they deliver but ordinary sense; and such perhaps he judg'd Guldinus's, and I doubt he might have some temptation to do so, if he did not light on very favourable passages; if he red his Dedica­tory, his Transitionary▪ his Discoursive parts even among his Demonstrations, strangely too talkative for a Mathematician. And though we agree Guldinus have truly ac­knowledg'd his error, yet not so openly, that he that runs may read it; he confesses pub­lickly, but 'tis in the corner of the Church: No Title of any the five Propositions, (lib. 2. c. 3.) where he treats directly of it, ex­pressing any mistake; but proposing still ei­ther to examin something about the Questi­on; or, to try how the Principle he had [Page] rely'd on, subsisted, &c. not, where it fail'd: so that his Retractation indeed, is there in print, yet so nicely touch't, and in so few words, and those mingled and almost lost among many others, that easily it might escape a less diligent Reader. Not that I mean, in this▪ entirely to justifie Chrysaspis, but rightly to state his fault; which is, that as it was free for him at first, to think the Book not worth his study, yet ought he not censure it without a full perusal.

But, if Chrysaspis judg'd too hastily; is that a crime beyond all pardon? are we not every one of us sometimes overseen? He that's innocent, let him throw the first stone; I'm sure he that threw the fi [...]fr stone at Chrysas­pis is not innocent for had be with impartial industry red over Guldinus, he might easily have found very many periods not so uncen­surable as he imagins. He complains that Guldinus is accus'd, and calls it unworthy, injurious, &c. and cites places out of his Book to acquit him. I ask, may not a Wri­ter be modest, humble▪ and solid, in some parts of his Book, and quite contrary in others? if I unhappily light upon these, am I not ex­cusable, in saying I dislike them? if your better fortune lead you to those, may you not commend as you see cause? Querela [Page] may exalt Guldinus, Chrysaspis may de­press him, both may have reason: and, in my conceit, all this is not onely possible, but true: for I see sometimes he discourses inge­niously and modestly; sometimes again tri­vially and vainly: This branch I must prove; the other Querela will freely grant; and two or three Instances I hope will dis­patch it. Onely here I desire to enter this Protestation, that I am really sorry the just defence of my best Friend, engages me to look into the faults of others, wherein I thank God, I take no delight.

To begin with a short account of the Book in generall, whereof first, I find a great part very little akin to the Title: and of that little, very much mechanically not Geometri­cally treated: and this, Guldinus freely ac­knowledges, and seems indeed by many pas­sages of his Book, to be a good natur'd man: He gathers out of others, most of his notions; of whose names he gives his Reader two fair Catalogues: in one of which, there are not many above thirty; but, in the other, almost fourscore. He professes most to meddle with the practical part, but tells you where to find the Demonstrations. His Collections are of­ten not pertinent to his end, but are many times, for all that, prety things in them­selves. [Page] The subjects he treats of are, some of them indeed hardly reducible to his pur­pose, as Algebra, numbers, ranging of Troops; besides, long Tables, &c. Yet are they all fit for Youth to learn, and that was the design of these his Labours, (as himself professes in his Preface to his third Book,) though afterwards collected & printed in Fo­lio: And will you now wonder, that one who us'd stil to be the best man in the Company he taught and daily triumpht among his Scho­lars, should be tainted at last with a little Vanity? for my part, I think it so shrewd a temptation, that few in such circumstances are observed to resist it.

But to come to the particulars: this spirit of Vanity may be plainly seen walking up and down his Book; I'm sure I met it often, espe­cially in his Epistles and Discourses which generally tast a little strong of the Scool­master. Turn but to the page 67. and read Ultimum ergo mirabilis illius lineae pun­ctum in quo nimirum vis omnis omneque momentum ac pondus circa Quadraturam Circuli consistit, quodque neque antiqui neque moderni, (interque illos nec nos ipsi) omnino geometrice determinant; ipsum tamen Centrum esse Gravitatis semiperi­pheriae circuli nos primùm mundo manifesta­mus. [Page] Wherefore, of that wonderful line, the last Point, in which all the force and all the moment and weight, in relation to the Quadrature of the Circle, consists; and which neither the Ancients nor the Moderns (nor among them we our selves) do altogether Geometrically determin; yet that it is the Center of Gravity of the Circles semicircumference, we first mani­fest to the World.

Will one more content you? see then the first Chapter of his third Book; where ha­ving briefly mention'd what the Ancients and Moderns had taught for measuring of round surfaces, and administring their Me­thods, begins thus of his own; Nos eam i­ta tractare constituimus, ut eandem ex so­lis & unicis nostris principiis, &c. pendere ostendamus—Quare etiamsi nullius al­terius Geometrae exstarent de Dimensione Rotundi lucubrationes, eam tamen ex his nostris sine ullo alio alterius auxilio expe­diemus. This is your modest man: does he not deserve to be enthron'd on a golden Chariot, and great Archimedes with him, and so both be led into the Capitol of e­ternal Honour? what else do his own words mean in his long Preface to the fourth Book? —Quem (Archimedem) aureo nobiscum [Page] sedentem curru in honoris perpetui arcem Capitolinam deducemus.

Run now over the rest of this great Vo­lume, and when you have wondred as you go at the vast variety of forreign subjects he has gathered together, pass on to the very end where you shall find a long and pleasant exercise, which will both need, and perhaps by its jolly humour, deserve your Courtesie to forgive a little tediousness. The mirth, I confess, came with some disadvantage to me, because I had formerly seen the substance of it elsewhere, though not so illustriously manag'd as by this Authour. 'Tis a curi­ous Arithmetical Problem, and begins pag. 351. Where after a short Rhetorical Intro­duction, he entertains his Reader with some prety little flourishes, to usher in the grand VVork. Firct he proposes the Case of 100 stones so dispos'd at several short distances, which so many times repeated unexpected­ly exceed five miles; and makes that side lose the VVager: then, puts another of a Horse, sold for so much a nail in every shooe, though, beginning at a very low price, but doubling Geometrically till the Buyer come to a dear bargain. A third, of one that in­vited 12 to dinner, &c. at last he arrives at the grand Question: How many several [Page] Combinations may be made of the 23 let­ters, which notwithstanding some restricti­ons, he reckons up in words at length, (and figures too) to no less a number then seventy thousand two hundred seventy three millions of millions, sixty seven thousand three hun­dred and thirty millions of millions; three hundred thirty thousand, ninety and eight millions, ninety one thousand one hundred fifty five words: Then in condescen­dence to his Auditors, he gathers all these words into a Book, just like that in his hand; counts how many pages in a leaf, how many lines in a page, how many letters in a line, then sums up the whole into a world of millions of millions, &c. and all this while, the Title of his Book is; Of the Center of Gravity.

But methinks I hear some of you mur­mur, says he, that you understand this but a little better then the other. To these he of­fers all imaginable satisfaction, first he sur­veys the bulk of every single Book, then proposes the gathering them into one Libra­ry, whose Model he describes, to say the truth, most exactly: sets down particu­larly the figure, which must be square, and is call'd sayes he, by Mathematicians, Cubical; then appoints the height, no less [Page] then that of St. Stephen's Tower, of which he gives you the measure to a foot. Then goes to the VValls, how high in themselves, how distant from one another, how many shelves each VVall can hold; how many Books each shelf, &c. then collects the same, not forget­ting what space the boards, and other little necessaries take up; and still the Title is, Of the Center of Gravity.

It remains, says he, that we consider the bredth: which he contrives to be filled with several rows, each regarding one another, (like our new Exchange) to the very mid­dle, yet providently allowing space for two to walk a brest in a Gallery between the shelves, besides what's requisite for Ladder's, to take down the Books; for both which pur­poses, he judges six foot and a half sufficient: then multiplying and dividing, he learnedly finds out the number of Libraries, capable to contain all these Volumes, to be eight thousand millions; not to speak of the 52 millions, &c. as being but an od number: I had almost forgot the Cover of the Library, which he cares not, though it be the Con­cave of the Moon it self.

Still they grudg, and he heares them mutter, that 'twere far easier to apprehend so intricate a mystery, by the quantity of ground [Page] these Libraries must be built on, then by their number. To these he professes he would willingly give satisfaction. But what Pro­vince, sayes he, what Kingdom, what Em­pire, of the Chineses, of the Turks, or of the Christians, or rather what World, the Old or the New shall we chuse for so vast a founda­tion? To be short, he will try it with the whole Globe of the Earth, let it be (sayes he) as big as it will, and not to lose time in gathering his Libraries into Cities onely, he takes in e­very inch of dry Land; and setting aside one moyety of the Globe for Waters, he casts up how many feet square the more diligent Mo­derns reckon are on the surface of the Earth, fifteen hundred millions of millions, &c. then assigns to every Library its due Plant, then sums up what number of them will cover the whole Earth, and at last, concludes they are two few for his work, by more then all our vastest Europe can hold.

If any have yet a curiosity, continues Guldinus to learn whether the said Books, being laid one by another, and close together, can cover the whole Globe, wet and dry, (for he doubts some foul play may be suspected in those large and many Galleries he left for Walks and Ladders, that might have held some millions of Books, and been perhaps suf­ficient [Page] without building Libraries on the Sea, which is little better then Castles in the Air) And here he judges it fit for a Com­plement of the Problem, that this suspition be taken away. To the triple reason: therefore he returns as manifold an answer, (I could not easily distinguish this triplicity of rea­sons; perhaps, if you will bestow so much time, you may at the bottom of the page 356) but to proceed, and end, I hope, ere long, for I am quite tired. Books, says he, may either stand thus on their ends, or on their long ed­ges, or so on their flat sides. The first way, they would overspread above seventeen such Globes as ours: the second, twice as many: the third, above a hundred such Worlds as these, might so be covered with our Books, (he meanes those he there speaks of) that not the least pins point of Earth should be seen.

And were not this enough to tempt any who loves a short and close method of wri­ting, to note with some sharpness such ex­travagancies? would you think any farther questions should be rais'd about this business, and that in a Treatise of the Center of Gra­vity? would you imagin he should ask how many Clarks were necessary, and how much time, to copy these Books? &c. Item (sayes [Page] he) whether or no the paper wherein they are written can cover and cloth, not the Earth, but Heaven it self, and the very Firmament, call'd by us the seat of the fixt Stars. He leaves, least he should seem to abuse the patience of their courtesie, to be considered by themselves at their leisure, Thus ends the famous Center of Gravity, and, with these pompous words, closes up it self, Viam ostendimus qua itur ad astra: and, if any serious Reader can forgive a Quibble, I think his Motto true and perti­nent, since, in my conceit, his Discourse goes quite away from the Center of Gravity, to the utmost bounds or Circumference of Le­vity.

Perhaps he may retract all this mirth in another place, and I be taken in the same crime with Chrysaspis; but I vow, I am not guilty of knowing any such correction; and, if there prove any, I am sure it must be in some by corner of the Book, else had it been in the open passages, I could not possibly have balk't it.

Besides, I doubt he is a little over-hasty too in his Censures, especially himself being guilty of the fault he charges on others; for having given us▪ as his own new Invention, (which I easily believe, it being not very ex­cellent) [Page] a little Treatise of the Center of Gravity, both of one and more indivisible Points: as also of Lines, he uses a liberty by supposing Points and Lines to have real Gravity, which he flatly denies to Cavale­rius, and somewhat roundly censures his call­ing a Surface, All the lines: and a Solid, All the surfaces; because no multitude of Mathematical lines, can make a surface, &c. And I pray, how many Mathematical points will weigh a pound? Why may not Cavale­rius as well take up a supposition so advan­cive of Mathematicks, and so approv'd by Mathematicians, as Guldinus demand the allowance of One neither beneficial nor ad­mitted; for should we comply with what he desires, as soon as a Point is considered to have Gravity, does it not immediately be­come of the Nature of a Solid? and then how is the World beholden to him for his new Invention? should we be froward and deny; how will he possibly prove that to have a Center of Gravity, which has no Gra­vity?

Nor was it injurious for Chrysaspis to tax Guldinus of unskilfulness in Mathe­maticks; when, (as 'tis rightly observed in Chrysaspis, Nota quarta) he offended a­gainst the very Definition of Inscribing and [Page] Circumscribing, and either knew not that the Inscrib'd line should with both its ends, touch the Circumscriber; or took two lines to perform the Circumscription instead of one: an error most gross and palpable, when once discover'd▪ an [...] so indeed are all mistakes in Geometry, though they may deceive some few for a while, as we see by experience, both in Guldinus and Chrysaspis.

Nor is Querela exempt from humanity, he is even a mortal too; and when he takes the Proportion of the Diameter to the Cir­cumference, to be as 7 to 22 he assumes what no Geometrician will allow, unless to Sur­veyers and Diallers, &c. but absolutely re­ject in an exact Calculation, which per­fect method I suspect was not very easie for him to attain; else surely when he stood up­on his honour, he would have us'd his ut­most diligence, especially this being his first Essay: for he never did any thing, that I know of, in print, but this Collection of the Errata's of Chrysaspis, and we shall see, even in so easie a task, he needs another to correct him. For he, making his Radius of four places, and not knowing, or not consider­ing the great difference that from thence ari­ses in the Proportion he follows, of 7 to 22 falls often, even himself, who so severely [Page] lashes others, into gross mistakes, as pag. 43. line 19. and 25. for 1047619 1/21 he should have put 1047197 ⅚ that is, greater then 1047197 5/10 and less then 1047197 6/10 for the Radius being 1000, the semicircumfe­rence is 3141 592/1000 6/7 according to Van Cul­len's numbers; and therefore the Circle is 3141592 6/7 and consequently the Sector EBFC 1047197 ⅚

P. 43. l. 21. and p. 44. for l. 23. 866. he should have said 866 025/1000 ⅘ BG. being 500 ℛ. 3. and consequently p. 43. l. 24. 433000. should have been 433012 ⅞

P. 44. l. 1. and p. 45. l. 8. and 14. for 614619 1/21 the more true is 614184 8/9

P. 44. l. 9. and 22. for 1802 7/9 ought to have been 1802 ⅞ because AG. is 500 ℛ 13.

[Page] P. 44. l. 11. and p. 45. l. 7. and 14. he puts 197 2/9 where he should have said 197 ⅔

P. 44. num. 2. He does not so much mi­stake, as which is far worse, discover him­self a very bungler in the skill he professes; for being to seek out the Angle BAE. he falls a hunting it in the oblique angled Triangle ABE. both the farther way about, and more intricate to find; whereas there lay plain before his eys a right angled Triangle BAG. with all the sides known in such numbers, that a bare inspection into the Canon gives the Angles; for half the number (which method I take as more conformable to the Tables) put for BG, considering onely the first four pla­ces in the Canon of Sines, gives the Angle BAG: and half the number put for GA, gives the Angle GBA. whose Complement is BAG.

Pag. 44 l. 17. 30 should have been left out, see Brigs's Canons.

P. 44. l. 20. and p. 45. l. 1. 1791126. ought to have been 1791289 ⅚

P. 44. l. 24. 1561205 5/9 ought to have been 1561249 4/ [...]

[Page] P. 45. l. 2.9.16. 230920 4/9 ought to have been 230040 0/1

P. 45. l. 18. 242433 ⅓ ought to have been 242264 ⅘

P. 45. l. 19. 11512 8/9 ought to have been 12224 ¾

In these mistakes, Querela either Copy'd the Tables of others; and then, why did he not chuse the more exact? or calculated all himself; and then, why did he not do it more exactly.

Perhaps he may say, his numbers are fa­vourabler to Chrysaspis, then the true ones: And it deserved acknowledgement▪ had it proceeded from kindness: but besides the un­expectableness in this case, of such a charity; who ever was known to hide their civilities so darkly, that one must seek the exactest Tables of Sines, and use so many figures to find them out? No, were Querela a perfect Master of Geometry, he had not been necessi­tated to so inferiour and unsevere a Me­thod; where, what never as yet was done, nor perhaps ever will be done, (the Quadrature of the Circle, and the precise exactness of [Page] the Canon of Sines:) is, in rigorous Geo­metry, unallowably suppos'd; both which in­conveniences were clearly avoided by that Learned and Noble Hand that with evi­dent and unexceptionable Arguments con­vinc't Chrysaspis, such as enforce the assent, without begging the Courtesie of a supposition.

But Querela may possibly answer, The errour was so plain, that there needed no more then the Doctrin of Triangles to con­fute it: I reply, how would Querela else have confuted it, the top of whose skill seems to reach no higher? nor indeed so high, with any just exactness, as his many mistakes have sufficiently discover'd.

And let him not complain of the easiness of his task; he quickly may find in Chrysas­pis's other Writings an employment worth his undertaking: Let him not cowardly tri­umph over One that had already yielded to a Noble Conquerour, and crost the Cudgels before Querela took 'em up; but manly be­gin with him on some worthy subject, fresh and unfoil'd by any other, and follow him close and roundly, and if he be but rigorously just, with as little mercy as he pleases; onely he is intreated not to harp perpetually on some one string that haply may displease him, but strike it a while, that it may be heard, then [Page] put it in tune, and go on to another; for I have often observ'd among the Dislikers of that eminent Author, the Parable of the hundred Sheep perversly verified, they leave the ninety nine just Opinions carlesly in the Wilderness; and all their zeal is bu­sie about the One that went astray; which when they have found, they lay on their shoulders, that all the World may see they have catch't him; and calling their Friends and Neighbours together, invite them to congratulate their happy fortune, that they have found, in a whole flock, one faulty sheep: whereas, were this excellent simili­tude duly understood and apply'd, we rather should endeavour to rectifie any single or rarely repeated errour of another; and re­joyce, not that it was committed, but that it is amended.

And here, to acquaint my Reader with the whole design I aim at by this invitation; I protest, it rises not from any the least hu­mour of provoking or making debates; but a hopeful desire, by such Discussions, more e­vidently to see, and more heartily embrace those solid truths, whom ever they belong to, that shall stand so severe a tryal; declaring openly before hand, this politick resolution, unblameable I hope in such engagements, to [Page] put my self still on the stronger side, and so be sure who ever overcomes, to have my share in the Victory.

Besides, a curious eye may note in Quere­la, some touches also of disingenuity, as p. 4. where he discourses, as if Chrysaspis should pretend he had never study'd Geometry: and p. 5. that he had not red so much as Eu­clide: and other little sleights of hand to help his Game: whereas the truth is, Chrysaspis says he never read over (or rather thorow­ly) so much as Euclide; nor ever profest to study Geometry; though in that very place he directly affirms, he had both study'd it for re­creation, and attain'd sufficient skill in it, to transfer its rigorous proceedings to Meta­physicks. All which Querela's Publisher ho­nestly acknowledges in his Translation of the Latin, p. 58. and I am glad my Name-sake is the fairer Gamester.

Nor will I here omit a Passage, wherein, I confess, I have not art enough entirely to ju­stifie either of them. Chrysaspis writes mi­stakably; and Querela mistakes him: the One might have exprest himself more plain­ly; the Other might have interpreted him more courteously: Both in some sense perhaps defendable; and in some sense both blamea­ble. Chrysaspis says, Guldinus was so [Page] vain, that when he thought he had com­mitted an errour, he could by no means be induced to cover it, by blotting it out; And so far is true, for he publisht it: or, candidly confess the same; Yet, all's well enough: for whoever reads Guldinus shall see, how long he rolls the sweet morsel in his mouth, before he can be perswaded to spit it out: but goes on framing excuses, as if in the very errour he had carried himself gal­lantly; And, does not he frame excuses, who after a plain Demonstration of his errour (and that, found out, as he says, by himself) puts down in the very next number, a Notandum that what he held was probabilissimum? and then proceeds to examin on both sides (as if the point were yet doubtful) which reasons are the stronger, and if any fail, how it comes to pass, and which are they, &c.

After these Advertisements, he immedi­ately advances this Proposition (of which al­ready I have given some touch) Detegere quomodo Principium &c. assumptum sub­sistat; not how it miscarries: for still he holds the Maxim, that deceiv'd him, true, though not universally; verum est, sed non universim ▪ which words must be meant in that sense wherein himself misunderstood [Page] the notion of Inscrib'd and Circumscrib'd; else as all the rest of the World interprets them, that Maxim is absolutely and univer­sally true. And, as to imagin what he call'd Inscrib'd to be less then the Circumscriber, was a prety Conjecture, and might not want hope to deceive, were it in some other Science then slow-believing Mathematicks; so, to take those lines to be inscrib'd, which had but one common term, was an intolerable Over­sight.

Now for the hardest task; that he bore himself as if he had done gallantly, thus much, even of that, he verifies: not onely speaking of his opinion as most probable, when he knew it to be false: nor onely min­cing the business, while he says, his Principle is true, though not universally: but, main­taining that the ground of what he affirmed was, to use his own odd expression, Commu­ne quasi in Geometricis assertum generale: and so plausible still, and dear to the good man was his own invention, that, at last, he sends his Reader once more to review the De­monstration that sustains his so probable Opi­nion; and then thus asks his judgement, an­non ea intellectum ipsius quodamodo ad assensum, si non omnino cogat, saltem sua­viter pertrahat?

[Page]This is the Crime that amaz'd Querela; this the foul and evident untruth against which he exclaims as a most unworthy and false Calumny, and maliciously imputed to Guldinus. Words of too fierce and rude a sense, for so mild a nature as Querela seems to have, whose choller sometimes may sim­ber a little, but surely never boyl over, un­less some hotter spirits blow the Coals; though perhaps once put into a heat, we know not when he may cease; but, let him carry on the metaphor a line or two farther, and it will faithfully give him this seasonable advice, that intemperate overflowings, both spill themselves, and diminish the fire that rais'd 'em.

And sure he was a little warmer then or­dinary, else what mean those angry and rash, and (which I am loath to say) untrue ex­pressions, pag. 30. Of all that Chrysaspis so maliciously here imputes to Guldin, there is not one word to be seen in him, nor the least ground or shadow in his wri­tings; yea, just the contrary to what is here so shamefully avouch't, &c. and p. 33. No man that has any worth in him, con­science, or morall honesty, would ever so unworthily have carried himself: And why so furious good Querela, against your [Page] Adversary? why so passionate for your friend? I'm sure you had not read over his whole Book when you wrote these underta­king words, not the least shadow in his writings. You affirm, he says, just the con­trary, and 'tis acknowledg'd, for he says al­most just the contrary to himself; besides, I must tell you (what already is sufficiently prov'd) there is more then one word to be seen, more then the least ground or sha­dow to justifie Chrysaspis his charge a­gainst Guldinus, of Vanity, unskilfulness, &c. for I find no pleasure in repeating ano­thers faults, if it were not necessary to the clearing of my Friend, and, I hope, should Querela seek any exception against my pro­ceeding, he will find my answer in his own.

Again, why so furious at this time, Querela, and upon this occasion? while your Antagonist oppos'd onely Tenets which you commonly call'd Articles of faith, you very neighbourly let him alone: while he did but evacuate all Christian Religion, and introduce a Pagan Philosophy, as o­thers accuse him, you patiently held your hands: but when he once presum'd to go too far, and touch one of your friends, then immediately you strike him on the face [Page] with malicious, shameful, nonsence, &c. then flies out Querela (true to his name) full of complaints and accusations, and bitter resentments.

And now, tell me for love of truth, how comes it to be lawful for the Opposers of Chrysaspis, to talk, and write, and act what they list against him; and he not permit­ted (who neither talks much, nor acts any thing against them,) to write a little in de­fence of himself? Remember how insolently his Vindicator provokes him, with Pagan Fa­tility, Epicurean Philosophy, Miscreant, Imp of Hell, &c. Remember how bitterly Querela reviles him, with false Calumnia­tor, notorious Detracter, a man of no worth, no conscience, nor moral honesty, &c. Remember how spitefully the ignorant followers of these principal Parties asperse him, abridging all the anger their Tutors teach 'em, into this compendious calumny, HERETICK. And when they have done all this, and more, and every day, and every where, immediately their rash and fro­ward passion will censure him, if he sit not down in a dull stupid indifferency, but shew himself sometimes a little sensible of their unreasonableness, in his Replies; which yet he does both very seldom, and onely by occa­sional [Page] touches where the subject invites him; not in downright railings and long inve­ctives, wherein his envious Adversaries too often excercize both their lungs and spleen against him.

But enough of this captious kind of con­tending, and too much indeed for an ingenu­ous mind, were it not unhappily countenanc'd by the common practise of all the Tribunals in the World, even spiritual as well as tem­poral; nay, in the inward Court of Consci­ence too, where the modern Casuists are al­lowed for Judges.

But, can we derive no profit from these miscarriages? sure if we had the art, we might extract good out of greater evils then the worst of these: And methinks I discern already, some advantages which perhaps may repair what the misadventures have lost.

Chrysaspis, by retracting this Demon­stration, has given us another, in a far more concerning affair; That when e're he shall be convinc'd of any error in his other works, he is ready ingeniously to disown it.

Querela, by discovering this mistake, may receive encouragement to search for more; an endeavour which as I hope would be very be­neficial to the World; so I am sure, very [Page] welcom to Chrysaspis: especially from Querela, whom, I have reason to say, (for his own hand has told me it) he really e­steems as a Person, in himself, of a good na­ture, and unpassionate temper. And if I may be permitted to interpose my conceit, I shall not doubt to affirm that both of them may more improve the World by confining hereafter their studies to their proper Pro­fession [...]; and do better right to themselves, by agreeing, for what's past, to forbear one another.

The friends of Chrysaspis, too often inju­riously charg'd as blind Adherers to his Do­ctrin, may fairly take hold on this occasion; and with one short question, silence all their Censurers. Which of us believe his Qua­drature? Confute but his other Opinions as we confess this may be done, and you soon shall see how few will follow him; And yet, (now I remember a letter, he did me the honour to send me in reference to this very business) we still shall follow him; for there he candidly professes in these express words, None of my friends need provide against following me in an errour, for soon as 'tis discover'd, my self shall be the first to go before them in forsaking it.

[Page]For Conclusion, I have onely this short wish to propose, That hereafter Chrysaspis may be warier in preventing the objections of his Adversaries; and Querela temperater in exalting the merits of his Friends; and both more severe in their Mathematicks, and less in their Censures. Which mildnes too, I humbly intreat of the ingenious Reader, to pardon my detaining him so long with super­ficial discourses, from passing on to the follow­ing more solid reasons: and accept▪ for my ex­cuse, this free acknowledgement; The shal­low water covers most ground, but the deep contains most substance.