"What is a pen?" The answer is, "An Instrument.” is wine?" "A Juice." "What 3. When you are asked, “What kind of instrument is a pen?" the answer would be, "One designed for writing;" or, "What kind of juice is wine?" "One extracted from grapes." This predicable is technically called the DIFFERENTIA, or difference. The difference and the genus are technically described as making up or constituting the species. 4. When any quality invariably and peculiarly belongs to a certain Species, but which yet is not that which we fix on as characterizing the Species, it is technically called the PROPERTY. Thus, inebriating is a "property" of wine, as we have seen; risibility is a "property" of man. 5. A predicable which belongs to some individuals of a Species, but not to others, is called an ACCIDENT; as a military dress is an accident of man, sweetness an accident of wine. EXERCISE. Mention which of these five relations the lower terms of the subjoined pairs sustain to the upper: Ex. g., is flower the species, genus, differentia, property, or accident of Rose? GENUS AND SPECIES. § 444. GENUS and Difference make up the SPECIES. Thus "animal" (the genus) and "rational" (the difference) constitute the "man." The Species, in reality, contains the Genus (i. e., implies it); and when the Genus is called a whole, and is said to contain the Species, this is only a metaphorical expression, signifying that it comprehends the Species in its more extensive, but less full (intensive) signification: e. g., if I predicate of Cæsar that he is an animal, I say the truth, indeed, but not the whole truth; for he is not only an animal, but a man, so that "man" is a more full and complete expression than "animal;" while "animal" is more extensive, as it comprehends several other species; as, Beast, bird, etc. In the same manner, the name of a species is a more extensive, but less full and complete term than that of an individual (viz., a singular term). A Genus which is also a species is called a SUBALTERNUM Genus or species, as "bird," which is the genus of "pigeon," a species, is itself a species of "animal." There may be more than one Subalternum. A Genus which is not considered as a species of any thing is called SUMMUM (the highest) Genus. A Species which is not considered as genus of any thing, but is regarded as containing under it only individuals, is called INFIMA, the lowest species. In enumerations it is illogical to rank higher and lower species together: thus, e. g., to speak of "Flowers" as being roses, lilies, water-lilies, would be illogical, the third article being manifestly included in the second. Genus, Name. § Summum . . . Body. Species, Infima . . . . A. Intension. Body B. Extension. Stone, plant, brute, man. Body with life and sensation . . . Brute, man. In the Summum Genus the Intension is least, the Extension greatest. In the Infima Species the Intension is greatest, the Extension least. In the following enumeration, specify the Illogical items: Compositions are, Histories, Poems, Odes, Orations, Essays. ABSTRACTION AND GENERALIZATION. § 445. ABSTRACTION is the process by which we notice some part or parts of the nature of an individual thing or object of perception and reflection, without considering for the time any other part or circumstance of its nature. Abstraction may also be described by a reference to its office as an instrument of reason, which is to notice those parts of several things in which they agree with one another. The word means a drawing away of their marks of agreement from all the distinctive marks which the single objects have. Thus we may abstract from all the houses which come in our way certain points of agreement (as that they are covered buildings, and fit for the habitation of men), and fix the attention upon these without regard to the points of difference (namely, the height, length, position, convenience, decoration). Thus, too, we may contemplate in the mind several different "Kings," putting out of our thoughts the name and individual character of each, and the terms and places of their reigns, and considering only the regal office which belongs to all and each of them; and we are thus enabled to designate any or every one of them by the common (or general) term "king," or, again, by the term Royalty we can express the circumstance which is common to them. It is by this drawing off that generalization is effected. But abstraction and generalization have not the same meaning. We can not "Generalize" without "abstracting," but we may perform Abstraction without Generalization. If, for instance, in the language of WHATELY, any one is thinking of the "sun" without having any notion that there is more than one such body in the universe, he may consider it without any reference to its place in the sky, whether rising or setting, or any other situation; or, again, he may be considering its heat alone, without thinking of its light; or of its light alone; or of its apparent magnitude, without any reference either to its light or heat. Now in each of these cases there would be Abstraçtion, though there would be no Generalization, as long as he was contemplating a single individual, that which we call the "Sun." But if he came to the belief that each of the fixed stars is a body affording light and heat of itself, as our sun does, he might then, by abstracting this common circumstance, apply to all and each of these, the Sun of our System and the Stars, one common term denoting that circumstance, calling them all "Suns." And this would be to Generalize. GENERALIZATION, then, is the act of Comprehending, under a Common name, several objects agreeing in some point which we abstract from each of them, and which that common name serves to indicate. A General name is one which is capable of being truly affirmed in the same sense of each of an indefinite number of things. An Individual or a Singular name is a name which is only capable of being truly affirmed in the same sense of one thing. When we refer two or more individuals to a species, or two or more species to a common Genus, we are said to Generalize. The processes of generalization and abstraction are employed in arriving at the logical distinctions of Genus and Species. EXERCISE I. 1. Abstract some quality from the other qualities in a field of Grass, and give a name to it. 2. Abstract from the character of Bonaparte certain qualities which fitted him to be a Tyrant, or certain qualities that fitted him to be a Warrior. Green or brave indicates a certain quality in the concrete, which we can abstract from the other qualities. Greenness or bravery is a quality in the abstract. While in the concrete it is a predicate, when in the abstract it is a subject. § 446. Logical DIVISION is a metaphorical expression to signify the distinct (i. e., separate) enumeration of several things signified by a common term or name. This is the exact oppo site of Generalization. It consists in the distribution of a Genus into its several species. For as in that you lay aside the differences by which several things are distinguished, so as to call them all by one common name, so in Division you add on the differences, so as to enumerate them by their several particular names. Thus "Mineral" is said to be divided into stones, metals, etc., and metals again into gold, iron, etc. These are called PARTS (or Members) of the division. An Individual is so called from its being incapable of being, in this sense, divided. Logical Division is different from Physical Division. What is true of a "logical whole" is true of each of its parts. What is true of a "physical whole" is not true of its parts. Logically, "tree" is divided into oak, elms, pine, etc. Physically, "tree" is divided into root, trunk, branches, etc. There may be two or more logical divisions of the same Genus. Thus "Book" may be divided according to the size; as, Quarto, octavo, etc.; or according to its matter; as, Poetical, historical, etc.; or according to its language; as, Latin, French, etc. The principle of the division must be adhered to from the first to the last. To begin with one principle and to introduce another, thus intermixing them, is to make a CROSS DIVISION. The rules for dividing correctly, in the language of WHATE LY, are, I. That the whole be exactly equal to all the Parts or Members together. Nothing, therefore, must be included of which the Genus can not be affirmatively predicated; nothing excluded of which it can. II. The Members [parts] must be contradistinguished, and not include one another, which they will do if you mix up together two or more kinds of division, made by introducing several distinct classes of differences. Thus, if you were to divide Books into Ancient, Modern, Latin, French, English, Quarto, Octavo, Poems, History, etc. (whereof a Modern book might be French or English, a Poem or a History, etc., a Quarto book Ancient or Modern), you would be mixing together four different kinds of division of Books, according to their Age, Language, Size, and Subject. And these are what are called Cross divisions, because they run across each other, |