five, restrictive, exceptive, or reduplicative propofition enters. Such propofitions are by fome called exponible, by others imperfectly modal. The rules given with regard to these are obvious, from a just interpretation of the propofitions.

The second class is that of hypothetical fyllogifms, which take that denomination from having a hypothetical propofition for one or both premises. Moft logicians give the name of hypothetical to all complex propofitions which have more terms than one subject and one predicate. I ufe the word in this large fense; and mean by hypothetical fyllogifms, all thofe in which either of the premifes confifts of more terms than two. How many various kinds there may be of fuch fyllogifms, has never been ascertained. The logicians have given names to fome; fuch as, the copulative, the conditional, by fome called hypothetical, and the difjunctive.

Such fyllogifins cannot be tried by the rules of figure and mode. Every kind would require rules peculiar to it. Logicians have given rules for fome kinds; but there are many that have not fo much as a name.

The Dilemma is confidered by most logicians as a fpecies of the disjunctive fyllogifm. A remarkable property of this kind is, that it may fometimes be happily retorted: it is, it seems, like a hand-grenade, which, by dextrous management, may be thrown back, so as to spend its force upon the affailant. We fhall conclude this tedious account of fyllogifms, with a dilemma mentioned by A. Gellius, and from him by many logicians, as info¬ luble in any other way.

Euathlus, a rich young man, defirous of learning the art of ་ pleading, applied to Protagoras, a celebrated fophift, to inftruct him, promising a great fum of money as his reward; one half "of which was paid down; the other half he bound himself to

..

pay as foon as he fhould plead a caufe before the judges, and VOL. II.

E e

gain

gain it. Protagoras found him a very apt fcholar; but, after "he had made good progrefs, he was in no hafte to plead cau"ses. The mafter, conceiving that he intended by this means to "fhift off his fecond payment, took, as he thought, a fure me"thod to get the better of his delay. He fued Euathlus before "the judges; and, having opened his cause at the bar, he pleaded to this purpose. O most foolish young man, do you not see, "that, in any event, I must gain my point? for if the judges give sentence for me, you must pay by their sentence; if against me, the condition of our bargain is fulfilled, and you "have no plea left for your delay, after having pleaded and gained a cause. To which Euathlus anfwered. O most wise master, "I might have avoided the force of your argument, by not pleading my own caufe. But, giving up this advantage, do you not fee, that whatever sentence the judges pass, I am safe? If they give sentence for me, I am acquitted by their sentence; "if against me, the condition of our bargain is not fulfilled, by my pleading a cause, and lofing it. The judges, thinking the arguments unanswerable on both fides, put off the cause to a t long day."

66

CHA P.

IN

CHA P. V.

Account of the remaining books of the Organon.

SECT. I. Of the Laft Analytics.

N the First Analytics, fyllogifms are confidered in refpect of their form; they are now to be confidered in respect of their matter. The form lies in the neceffary connection between the premises and the conclufion; and where fuch a connection is wanting, they are said to be informal, or vicious in point of form.

But where there is no fault in the form, there may be in the matter; that is, in the propofitions of which they are compofed, which may be true or false, probable or improbable.

When the premises are certain, and the conclufion drawn from them in due form, this is demonftration, and produces fcience. Such fyllogifms are called apodictical; and are handled in the two books of the Laft Analytics. When the premises are not certain, but probable only, fuch fyllogifins are called dialectical; and of them he treats in the eight books of the Topicks. But there are fome fyllogifms which feem to be perfect both in matter and form, when they are not really fo: as, a face may feem beautiful which is but painted. These being apt to deceive, and produce a false opinion, are called fophiftical; and they are the subject of the book concerning Sophifms.

To return to the Laft Analytics, which treat of demonftration

and of science: We fhall not pretend to abridge those books; for Ariftotle's writings do not admit of abridgement: no man can fay what he fays in fewer words; and he is not often guilty of repetition. We fhall only give some of his capital conclufions, omitting his long reafonings and nice diftinctions, of which his genius was wonderfully productive.

All demonstration must be built upon principles already known; and these upon others of the fame kind; until we come at last to first principles, which neither can be demonftrated, nor need to be, being evident of themselves.

We cannot demonftrate things in a circle, fupporting the conclufion by the premises, and the premises again by the conclufion. Nor can there be an infinite number of middle terms between the first principle and the conclufion.

In all demonstration, the first principles, the conclufion, and all the intermediate propofitions, must be neceffary, general, and eternal truths for of things fortuitous, contingent, or mutable, or of individual things, there is no demonstration.

Some demonftrations prove only, that the thing is thus affected; others prove, why it is thus affected. The former may be drawn from a remote cause, or from an effect: but the latter must be drawn from an immediate caufe; and are the moft perfect.

The first figure is beft adapted to demonftration, because it affords conclufions univerfally affirmative; and this figure is commonly used by the mathematicians.

The demonstration of an affirmative propofition is preferable to that of a negative; the demonstration of an univerfal to that of a particular; and direct demonstration to that ad abfurdum.

The principles are more certain than the conclusion.

There cannot be opinion and fcience of the fame thing at the fame time.

In the fecond book we are taught, that the questions that may

be

be put, with regard to any thing, are four : 1. Whether the thing be thus affected. 2. Why it is thus affected. 3. Whether it exifts. 4. What it is.

The last of these questions Aristotle, in good Greek, calls the What is it of a thing. The schoolmen, in very barbarous Latin, called this, the quiddity of a thing. This quiddity, he proves by many arguments, cannot be demonftrated, but must be fixed by a definition. This gives occafion to treat of definition, and how a right definition should be formed. As an example he gives a definition of the number three, and defines it to be the first odd number.

In this book he treats alfo of the four kinds of caufes; efficient, material, formal, and final.

Another thing treated of in this book is, the manner in which we acquire first principles, which are the foundation of all demonstration. Thefe are not innate, because we may be for a great part of life ignorant of them: nor can they be deduced demonftratively from any antecedent knowledge, otherwise they would not be first principles. Therefore he concludes, that first principles are got by induction, from the informations of fenfe. The fenfes give us informations of individual things, and from these by induction we draw general conclufions: for it is a maxim with Aristotle, That there is nothing in the understanding which was not before in fome fense.

The knowledge of first principles, as it is not acquired by demonftration, ought not to be called fcience; and therefore he calls it intelligence.

SECT.