« ForrigeFortsæt »
the name of Aristotle's Organon or his Logic; and
many ages, Porphyry's Introduction to the Categories has been prefixed to them.
Sect. 2. Of Porphyry's Introduction. In this introduction, which is addressed to Chrysoarius, the author observes, That in order to understand Aristotle's doctrine concerning the categories, it is necessary to know what a genus is, what a species, what a specific difference, what a property, and what an accident ; that the knowledge of these is also very useful in definition, in division, and even in demonstration: therefore he proposes, in this little tract, to deliver shortly and simply the doctrine of the ancients, and chiefly of the Peripatetics, concerning these five predicables ; avoiding the more intricate questions concerning them; such as, Whether genera and species do really exist in nature ? or, Whether they are only conceptions of the human mind? If they exist in nature, Whether they are corporeal or incorporeal ? and, Whether they are inherent in the objects of sense, or disjoined from them? These, he says, are very difficult questions, and require accurate discussion ; but that he is not to ineddle with them.
After this preface, he explains very minutely each of the five words above mentioned, divides and subdivides each of them, and then pursues all
the agreements and differences between one and another through sixteen chapters.
Sect. 3. Of the Categories. The books begins with an explication of what is meant by univocal words, what by equivocal, and what by denominative. Then it is observed, that what we say is either simple, without composition or structure, as man, horse ; or, it has composition and structure, as, a man fights, the horse runs. Next comes a distinction between a subject of predication; that is, a subject of which any thing is affirmed or denied, and a subject of inhesion. These things are said to be inherent in a subject, which, although they are not a part of the subject, cannot possibly exist without it, as figure in the thing figured. Of things that are, says Aristotle, some may be predicated of a subject, but are in no subject; as man may be predicated of James or John, but is not in any subject. Some again are in a subject, but can be predicated of no subject. Thus, my knowledge in grammar is in me as its subject, but it can be predicated of no subject ; because it is an individual thing. Some are both in a subject, and may be predicated of a subject, as science ; which is in the mind as its subject, and may be predicated of geometry. Lastly, Some things can neither be in a subject, nor be predicated of any subject. Such are all individual substances, which cannot be predicated, because they are individuals ;
and cannot be in a subject, because they are substances. After some other subtilties about predicates and subjects, we come to the categories themselves ; the things above mentioned being called by the schoolmen the anteprædicamenta. It may be observed, however, that notwithstanding the distinction now explained, the being in a subject, and the being predicated truly of a subject, are in the Analytics used as synonymous phrases; and this variation of style has led some persons to think that the Categories were not written by Aristotle.
Things that may be expressed without composition or structure, are, says the author, reducible to the following heads. They are either substance, or quantity, or quality, or relatives, or place, or time, or having, or doing, or suffering. These are the predicaments or categories. The first four are largely treated of in four chapters ; the others are slightly passed over, as sufficiently clear of themselves. As a specimen, I shall give a summary
of what he says on the category of substance.
Substances are either primary, to wit, individual substances, or secondary, to wit, the genera and species of substances. Primary substances neither are in a subject, nor can be predicated of a subject; but all other things that exist, either are in primary substances, or may be predicated of them. For whatever can be predicated of that which is in a subject, may also be predicated of the subject itself. Primary substances are more substances than the secondary; and of the secondary, the species is more a substance than the genus. If there were no primary, there could be no secondary substances.
The properties of substance are these : 1. No substance is capable of intension or remission. 2. No substance can be in any other thing as its subject of inhesion. 3. No substance has a contrary ; for one substance cannot be contrary to another; nor can there be contrariety between a substance and that which is no substance. 4. The most remarkable property of substance, is, that one and the same substance, may, by some change in itself, become the subject of things that are contrary. Thus, the same body may be at one time hot, at another cold.
Let this serve as a specimen of Aristotle's manner of treating the categories. After them, we have some chapters, which the schoolmen call postprædicamenta ; wherein first, the four kinds of
opposition of terms are explained; to wit, relative, privative, of contrariety, and of contradiction. This is repeated in all systems of logic. Last of all we have distinctions of the four Greek words which answer to the Latin ones, prius, simul, motus, and habere.
SECT. 4. Of the book concerning Interpretation.
We are to consider, says Aristotle, what a noun is, what a verb, what affirmation, what negation,
what speech. Words are the signs of what passeth in the mind; writing is the sign of words. The signs both of writing and of words are different in different nations, but the operations of mind signified by them are the same. There are some operations of thought which are neither true nor false. These are expressed by nouns or verbs singly, and without composition.
A noun is a sound, which, by compact, signifies something without respect to time, and of which no part has signification by itself. The cries of beasts may have a natural signification, but they are not nouns; we give that name only to sounds which have their signification by compact. The cases of a noun, as the genitive, dative, are not nouns. Non homo is not a noun, but, for distinction's sake, may be called a nomen infinitum.
A verb signifies something by compact with relation to time. Thus valet is a verb; but valetudo is a noun, because its signification has no relation to time. It is only the present tense of the indicative that is properly called a verb; the other tenses and moods are variations of the verb. Non valet may
be called a verbum infinitum. Speech is sound significant by compact, of which some part is also significant. And it is either enun. ciative, or not enunciative. Enunciative speech is that which affirms or denies. As to speech which is not enunciative, such as a prayer or wish, the consideration of it belongs to oratory, or poetry.