Account of the remaining books of the Organon.

SECT. 1. Of the Laft Analytics.

N the First Analytics, fyllogifms are confidered in

in refpect of their matter. The form lies in the necef fary connection between the premises and the conclufion; and where fuch a connection is wanting, they are. faid 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 falfe, probable or improbable.

When the premises are certain, and the conclufion. drawn from them in due form, this is demonstration, and produces fciences. Such fyllogifms are called apodidical; and are handled in the two books of the Last Analytics. When the premises are not certain, but probable only, fuch fyllogifms are called dialectical; and of them he treats in the eight books of the Topics. But there are fome fyllogifms which seem to be perfect both in matter and form, when they are not really fo: as, a face feem beautiful which is but painted.. Thefe being apt to deceive, and produce a false opinion, are called fophiftical; and they are the fubject of the book concerning Sophifms.

may

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 abridgment: no man can say what he fays in fewer words; and he is not often guilty of repetition. We fhall only give fome of his capital conclufions, omitting his long reafonings and nice diftinctions, of which his genius was wonderfully productive.

All demonftration 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.

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We cannot demonftrate things in a circle, fupporting the conclufion by the premifes, 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 demonftration, the first principles, the conclufion, and all the intermediate propofitions, muft be neceffary, general, and eternal truths: for of things for tuitous, 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 caufe, or from an effect; but the latter must be drawn from an immediate caufe; and are the most perfect.

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

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

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

The laft of thefe queftions Ariftotle, in good Greek, calls the What is it of a thing. The fchoolmen, 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 fhould be formed. As an example he gives a definition of the number three, and defines it to be the firft 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 firft principles, which are the

foundation

foundation of all demonftration. These 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, otherwife 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 thefe 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 fenfe.

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

SECT. 2. Of the Topics.

The profeffed defign of the Topics, is, to fhew a method by which a man may be able to reason with probability and confiftency upon every question that inay.

Occur.

Every queftion is either about the genus of the fubject, or its specific difference, or fome thing proper to it, or fomething accidental.

To prove that this divifion is complete, Ariftotle reafons thus: Whatever is attributed to subject, it must either be, that the fubject can be reciprocally attributed to it, or that it cannot. If the fubject and attribute can be reciprocated, the attribute either declares what the fubject is, and then it is a definition; or it does not declare what the fubject is, and then it is a property. If the attribute cannot be reciprocated, it must be fomething contained in the definition of the fubject, it must be the genus of the fubject, or its fpecific difference; for the definition confifts of these two. If it is not contained in the definition of the subject, it must be an accident.

The furniture proper to fit a man for arguing dialectically may be reduced to thefe four heads: 1. Probable propofitions of all forts, which may on accafion be afTumed in an argument. 2. Distinctions of words which are nearly of the fame fignification. 3. Diftinétions of

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Book III. things which are not fo far afunder but that they may be taken for one and the fame. 4. Similitudes.

The fecond and the five following books are taken up in enumerating the topics or heads of argument that may be used in queftions about the genus, the definition, the properties, and the accidents of a thing; and occafionally he introduces the topics for proving things to be the fame, or different; and the topics for proving one thing to be better or worse than another.

In this enumeration of topics, Aristotle has fhewn more the fertility of his genius, than the accuracy of method. The writers of logic feem to be of this opinion: for I know none of them that has followed him clofely upon this fubject. They have confidered the topic of argumentation as reducible to certain axioms. For instance, when the question is about the genus and fpecies; when it is about definition, it must be determined by fome axiom relating to definition, and things defined and fo of other questions. They have therefore reduced the doctrine of the topics to certain axioms or canons, and difpofed thefe axioms in order under certain heads.

This method seems to be more commodious and elegant than that of Ariftotle. Yet it must be acknowledged, that Ariftotle has furnished the materials from which all the logicians have borrowed their doctrine of topics: and even Cicero, Quintilian, and other rhetorical writers, have been much indebted to the topics of Ariftotle.

He was the first, as far as I know, who made an attempt of this kind: and in this he acted up to the magnanimity of his own genius, and that of ancient philofophy. Every fubject of human thought had been reduced to ten categories; every thing that can be attributed to any fubject, to five predicables: he attempted to reduce all the forms of reafoning to fixed rules of figure and mode, and to reduce all the topics of argumentation under certain heads; and by that means to collect as it were into one ftore all that can be faid on. one fide or the other of every queftion, and provide a grand arsenal, from which all future combatants might

be

be furnished with arms offenfive and defenfive in every caufe, fo as to leave no room to future generations to invent any thing new.

The last book of the Topics is a code of the laws, according to which a fyllogiftical difputation ought to be managed, both on the part of the affailant and defendant. From which it is evident, that this philofopher trained his difciples to contend, not for the truth merely, but for victory.

SECT. 3. Of the book concerning Sophisms.

A fyllogifin which leads to a falfe conclufion, muft be vicious either in matter or form: for from true principles nothing but truth can be justly deduced. If the matter be faulty, that is, if either of the premises be falfe, that premise must be denied by the defendant. If the form be faulty, fome rule of fyllogifm is tranfgreffed; and it is the part of the defendant to fhew, what general or fpecial rule it is that is tranfgrefsed. So that, if he is an able logician, he will be impregnable in the defence of truth, and may refift all the attacks of the fophift. But as there are fyllogifms which may feem to be perfect both in matter and form, when. they are not really fo, as a piece of money may feem to be good coin, when it is adulterate; fuch fallacious fyllogifms are confidered in this treatife, in order to make a defendant more expert in the ufe of his defenfive weapons.

And here the author, with his ufual magnanimity, attempts to bring all the fallacies that can enter into a fyllogifm under thirteen heads; of which fix lie in the diction on language, and feven not in the diction.

The fallacies in diction are, 1. When an ambiguous word is taken at one time in one fenfe, and at another time in another. 2. When an ambiguous phrafe is taken in the fame manner. 3. and 4. are ambiguities in fyntax; when words are conjoined in fyntax that ought to be disjoined, or disjoined when they ought be conjoined. 5. is an ambiguity in profody, accent or pronunciation. 6. An ambiguity arifing from fome figure of speech.

When a fophifm of any of thefe kinds is tranflated into another language, or even rendered into unambi

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