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negative; but an affirmative and a negative are contrary in their quality.
When the fubject of a propofition is a general term, the predicate is affirmed or denied, either of the whole, or of a part. Hence propofitions are diftinguished into univerfal and particular. All men are mortal, is an univerfal propofition; Some men are learned, is a particular; and this is called the quantity of the propofition. All univerfal propofitions agree in quantity, as alfo all particular: but an univerfal and a particular are faid to differ in quantity. A propofition is called indefinite, when there is no mark either of univerfality or particularity annexed to the subject: thus, Man is of few days, is an indefinite propofition; but it must be understood either as univerfal or as particular, and therefore is not a third fpecies, but by interpretation is brought under one of the other two.
There are alfo fingular propofitions, which have not a general term but an individual for their fubject; as, Alexander was a great conqueror. These are confidered by logicians as univerfal, because, the fubject being indivifible, the predicate
is affirmed or denied of the whole, and
Afferit A, negat E, fed univerfaliter ambæ ;
When the young logician is thus far inftructed in the nature of propofitions, he is apt to think there is no difficulty in analyfing any propofition, and fhewing its fubject and predicate, its quantity and quality; and indeed, unless he can do this, he will be unable to apply the rules of logic to ufe. Yet he will find, there are fome difficulties in this analysis, which are overlooked by Ariftotle altogether; and although they are fometimes touched, they are not removed by his followers. For, 1. There are propofitions in which it is difficult to find a fubject and a predicate;
as in these, It rains, It Snows. 2. In fome - propofitions either term may be made the fubject or the predicate as you like beft; as in this, Virtue is the road to happiness. 3. The fame example may ferve to fhew, that it is fometimes difficult to fay, whether a propofition be univerfal or particular. 4. The quality of fome propofitions is fo dubious, that logicians have never been able to agree whether they be affirmative or negative; as in this propofition, Whatever is infentient is not an animal. 5. As there is one clafs of propofitions which have only two terms, to wit, one fubject and one predicate, which are called categorical propofitions; fo there are many claffes that have more than two terms. What Ariftotle delivers in this book is applicable only to categorical propofitions; and to them only the rules concerning the converfion of propofitions, and concerning the figures and modes of fyllogifms, are accommodated. The subsequent writers of logic have taken notice of fome of the many claffes of complex propofitions, and have given rules adapted to them; but finding this work endless, they have left us to manage the reft by the rules of common fenfe. CHAP.
Account of the First Analytics.
SECT. I. Of the Converfion of Propofitions,
N attempting to give fome account of
the Analytics and of the Topics of Ariftotle, ingenuity requires me to confefs, that though I have often purposed to read the whole with care, and to understand what is intelligible, yet my courage and patience always failed before I had done. Why fhould I throw away fo much time and painful attention upon a thing of so little real ufe? If I had lived in thofe ages when the knowledge of Aristotle's Organon intitled a man to the highest rank in philofophy, ambition might have induced me to employ upon it fome years of painful study; and lefs, I conceive, would not be fufficient. Such reflections as thefe, always got the better of my refolution,
when the first ardor began to cool. All I can fay is, that I have read fome parts of the different books with care, fome flightly, and fome perhaps not at all. I have glanced over the whole often, and when any thing attracted my attention, have dipped into it till my appetite was fatisfied. Of all reading it is the most dry and the most painful, employing an infinite labour of demonstration, about things of the most abstract nature, delivered in a laconic style, and often, I think, with affected obfcurity; and all to prove general propofitions, which when applied to particular instances appear self-evident.
There is probably but little in the Categories or in the book of Interpretation, that Ariftotle could claim as his own invention: but the whole theory of fyllogifms he claims as his own, and as the fruit of much time and labour. And indeed it is a fiately fabric, a monument of a great genius, which we could wish to have been more usefully employed. There must be fomething however adapted to please the human understanding, or to flatter human pride, in a work which occupied men of fpeculation for more than a thoufand