and then, yet it paffes unobserved, and their Darkness is their protection: Whereas, when a Man writes clearly and diftinctly, and explains things of great Abftrufity upon clear and intelligible Prin ciples, and in a perfpicuous Manner and Method, he holds out a Light to his Reader whereby to difcover his own Defects, and 'tis then eafie to fee whether he fucceeds well or no in what he undertakes: For when 'tis once conceived what 'tis a Man means, 'twill not be very difficult to difcern whether what he means be true. So that a Man that shall write clearly, had need advance that which is true and folid, or elfe his own Light will betray him. As a Man that has a light Shop had need fell good Ware. Clear Writing then is not always the beft Policy, but 'tis the best Honefty and Ingenuity, and that's better than Policy, or all the falfe Colours of a corrupt and impofing Eloquence.

For the avoiding of which I have thought it convenient to use great plainnefs and chaftness of Style, and to express my felf not only Scholaftically, but even fometimes Syllogiftically, as being not out of conceit with Syllogifm, notwithStanding the late Addrefs wherewith a well known Author has endeavour'd to disparage it, and bring it into difefteem: Which indeed feems not much less paradoxical and furprizing than to Speak against Reafoning itfelf: For what is Syllogifm, but only a more recollected and express way of Reasoning, the putting together all the parts of an Argument, and nothing but thofe Parts, and that in their

due

due Form and Order. To Syllogize is an Arithmetical Term fignifying the making up of an Account, or the Collection of the fum of feveral Numbers, whence, by an apt Traduction it is applied to fignifie that form of Argumentation, which, for the proportion it bears to it, we call by the Name of Syllogifm, for Syllogifm is a fort of Numeration; that is, it is that in Reasoning or Logick, which Addition is in Arithmetick, viz. The laying together, or affembling the particular fums, and thence deducing the fum total or product of the whole. The particular Sums or Items, are the Premises or the fum Total refulting from them, is the Conclufion. Which, tho" potentially in the Premifes, as the fum Total is in the particular fums, yet is really diftinct from them, and indeed more than the fum Total is from the Items; the diftinction here being only formal, whereas the Conclufion is a propofition really diftinct from the Premifes, as having but one only Term in common with each of them. To talk againft Syllogifm therefore in Reasoning, is like talking against Addition in Numbring, or cafting Account. And a Man cannot talk rationally against it, without the practical Contradiction of falling into it, fince 'tis that whereof all rational Difcourfes confift, and into which it finally refolves : For there is nothing strictly rational in any Dif courfe but what is either a premife of one fort or other, or a Conclufion. And whatever upon a due fecretion or Separation is found to be neither

of

of thefe, whatever Figure it may otherwife feem to make, or of what ufe foever it may really be in other refpects (as Definitions and Diftinctions for the right stating of the thing in Queftion,or Divifion for the more diftinct and orderly proceeding in it) is yet the Account. So that the Syllogifm, at leaft materially confidered, is fo much of the very Effence of Reasoning, that 'tis impoffible to dif courfe rationally out of it. 'Tis true indeed, the parts may not be all exprefly fet down, nor thofe that are, duly ranged and difpofed in their proper Order (which is all the difference that I know between a rational Difcourfe at large, and a formal Syllogifm) but then what is wanting in each of thefe, must be mentally fupplied, or else the Argument is imperfect; and if it be fupplied, then tis a Syllogifm.

All the Queftion here will be whether a Conclufion may not immediately follow upon the premifal of one fingle Propofition. This indeed feems to be favour'd by the ordinary way of speaking, as when we fay, that this, or that is the Confequence of this or that Principle; and fo the fore-defigned Author feems to intimate, when he tells us, That to infer is nothing, but by vertue of one Propofition laid down as true, to draw in another as true. And the Inftances he gives of Reasoning, are of this kind, as confifting of Inferences deduced from fingle Principles. But as far as I un-. derstand what belongs to Reasoning (which perhaps I am now convincing the World is but littlej

there.

there can be no Confequence justly drawn from one folitary Propofition. There must be two Premifes to fupport à Conclufion, understood at least if not expreffed, and that for this clear Reason, because the truth of the Conclufion as a Conclufion, or the force of the Illation depending upon the Union or Argreement which each of the extreams has with that intermediate Idea to which, as to a common Meafure, they are applied (for even according to our Author, 'tis by vertue of the perceived Agreement of this Idea with the Extreams, that the Extreams are concluded to agree among themselves) there is a necessity that each of them should be diftinctly applied to it, that fo from their agreement with it, they may appear to agree with one another. And the Several Application of this middle Idea to each of the Extreams, makes the two Propofi tions antecedent to the Conclufion, which accordingly we call Premifes. But an inftance in Geometry (which indeed is the best Logick) will fufficiently clear this Matter. In every Triangle the greatest Angle is opposed to the greateft Side, let that be the Propofition. Now from this Propofttion, which is the ninteenth of Euclid, it may be Said to follow, and 'tis a Corollary which a Mathematician of note draws from it, that if from a Point out of a right Line, one draws upon this Line as many right Lines as one pleafes; as fuppofe

.

A

AB, AC, AD, AE, one of which, namely, AB is Perpendicular,this Perpendicular will be the leaft or shortest of them all, fince it will be oppofed to, or fuftain an Acute Angle, fuch as C, D, and E, all of them are; whereas the others will be oppofed to, or fuftain a right EDCB Angle, fuch as is B. The fum

of which Argument is in effect this; That is the leaft fide which is opposed to the leaft Angle, therefore A B is the leaft fide; or, to take the Minor instead of the Major, AB is oppofed to the leaft Angle, and therefore A B is the leaft fide; which Seems a Confequence drawn from one only Propofition. But, 'tis plain, that this is an imperfect Argument, unless more is understood than is here expreffed: And that to make it perfect and conclufive, it must be reduced to this or the like Form. That is the leaft fide which is oppofed to the leaft Angle. But AB is oppofed to the leaft Angle, as being opposed to an Acute one, C. Therefore AB is the leaft fide; whereby it appears, that tho' in a popular way of Speaking, a Confequence may be faid to follow upon one Propofition, as laying the main Ground upon which the Argument that proves or infers it may be built, yet another must be added to it before it actually and truly does or can follow. And when it is added, then what is the Argument but a Syllogifm? Against which therefore

it