ments are the Subject, the Predicate, and the Copula, is the province of Logic. To state that such a sentence as Thou art speaking is correct, having reference only to the parts of speech and their arrangement, is a part of Grammar. To show the difference, in force of expression, between such a sentence as Great is Diana of the Ephesians, and Diana of the Ephesians is great, is a point in Rhetoric.

Grammar, Logic, and Rhetoric, then, each being thus connected with language, are united by something more than the commune vinculum, the common bond which unites the several branches of Knowledge. They constitute the famous Trivium of the ancient schools; while the other branches of learning, namely, Arithmetic, Geometry, Music, and Astronomy, the Quadrivium; as in these two hexameters, framed to assist the memory:

GRAM., loquitur; DIA., vera docet; RHET., verba colorat;

Mus., canit; AR., numerat; GEO., ponderat; AST., colit astra.

A thorough knowledge of any one of the three can not be obtained without an acquaintance with the two others.

§ 440. There are, moreover, Historical reasons why a thorough knowledge of grammar can not be obtained without a previous acquaintance with logic. Grammar grew up out of logic, and still retains some of the features of its origin. The early Greek grammarians transferred the terms of logic, many of them, to grammar. Those same terms are still employed by some of the best German, French, and English grammarians, Thus the term predicate, used in grammar, was derived from logic. In order, therefore, to understand those terms in their full and exact meaning, the study of logical forms is a prerequisite.

VALUE OF THIS PART OF THE WORK.

§ 441. As Grammatical forms existed before a system of Grammar had been devised, so Logical forms existed in language before any system of Logic. It is the office of Logic to observe, to classify, and arrange these forms, in order that they may be used understandingly and correctly for the purposes of reasoning.

It is foreign to the aim of the present work to exhibit either the Science or the Art of Logic, in the development of its principles or of its rules. All that is attempted is to present some of the Forms of Logic, which, in other words, are but Forms of Language. "Logic," says WHATELY, "is wholly concerned in the use of Language." If men understood distinctly the forms of logic, that is, the appropriate language of reasoning, they would be more apt to come to the same conclusions. They would be more apt to avoid a misunderstanding, which, in common parlance, is equivalent to quarrel.

As an encouragement to the study of this Fifth Part of the present work, it should be added, that Logical forms are the same, to whatever subject of reasoning they are applied, whether, for instance, to questions connected with government, education, or religion. As men, especially intelligent men, will reason, they ought to understand and to use the correct forms of language for expressing their reasoning.

QUESTIONS UNDER CHAPTER I.

1. What definitions have been given to logic?
2. How has the Greek word 2óyos been defined ?

3. With what is logic concerned?

4. What are logical forms?

5. State the relations between logic, grammar, and rhetoric.
6. State the historical connection between grammar and logic.
7. Which was prior in existence, logic or logical forms?
8. State what is the aim of this work in respect to logic.

9. State what is the value of a knowledge of the forms of logic.

10. Are logical forms the same, though applied to different subjects?

CHAPTER II.

TERMS.

§ 442. THE word TERM in Logic is from the Latin terminus (Greek Tépua), a boundary or end. In a proposition there are two ends or extremities, viz., the Subject and Predicate, between which stands the Copula. Thus, in the proposition, John is wise, John the subject, and wise the predicate, are the terms= termini, connected by the copula is. The Subject and Predicate are the terms of a proposition. A term is the name of any object of contemplation. Of these objects, some are substances and some are attributes.

1. Terms or names which stand for a class of things are called COMMON; as, River, tree, city.

2. Terms or names which represent a single thing only are called SINGULAR; as, The Potomac, charter-oak, Boston.

3. Terms or names which express objects, of which one, as father, implies the existence of the other, as son, are called COR

RELATIVE.

4. Terms or names which represent qualities which inhere in some subject, such as wise, hard, prudent, are called CONCRete.

5. Terms or names which represent qualities which do not thus inhere, but exist by themselves, such as wisdom, hardness, prudence, are called ABSTRACT.

6. Terms or names related to each other, as are wise and foolish, hard and soft, prudent and reckless, are called CONTRARY. These denote only the most widely different in the same class.

7. Terms or names related to each other, as are organized and unorganized, material and immaterial, belief and disbe lief, the one being a direct negative of the other, both being applicable to objects not in the same class, are called CONTRA

DICTORY.

8. Terms or names related to each other, as are wise and foolish, which can not be applied to the same person at the same time, are called INCOMPATIBLE.

9. Terms or names which are related to each other, as are

wise and worthy, which can be applied to the same person at the same time, are called COMPATIBLE.

10. A term or name which expresses an object of simple apprehension is called a SIMPLE TERM; as, A man, a tree. See § 464.

11. A term made up of a combination of words which expresses a complex apprehension is called a COMPLEX TERM; as, A man with a sword; a tree covered with snow. A term A term may be made up of several words, still it expresses but one thing. See § 464.

12. A term used in only one sense is called UNIVOCAL. A term used in more senses than one is EQUIVOCAL. Take, for example, the word "Case," used to signify a kind of covering; and, again, an inflection of a noun, as John's, in the possessive "case;" and, again, a "case" such as is laid before a lawyer. This word is, in sense, three words; and in each of the three senses it may be applied "univocally" to several things which are, in that sense, signified by it. But when applied indiscriminately to a "covering" and to a grammatical case, it is used equivocally."

2. Name the terms in the following sentence: "It was believed that reality and truth were limited to experience, and experience was limited to the sphere of sense; while the very highest faculties of the mind were deemed adequately explained when recalled to perceptions elaborated, purified, sublimated, and transformed. From the mechanical relations of sense with its object, it was attempted to solve the mysteries of will and intelligence; the philosophy of mind was soon viewed as correlative to the physiology of organization. The moral nature of man was at last formally abolished in its identification with his phys

ical; mind became a reflex of matter; thought a secretion of the brain."-Sir WM. HAMILTON'S Review of Cousin's Lectures.

PREDICABLES.

§ 443. In the language of the schools there were FIVE PREDICABLES, i. e., Five things, one or other of which must be affirmed, i. e., predicated, wherever any thing is affirmed concerning another thing, as in the following example :

1. Wine is the SPECIES, or subordinate Class.

1

2

3

4

5

2. Juice is the GENUS, or Class in which wine is included. 3. The quality which distinguishes "wine" from all other "species" of juice is its being "extracted from grapes;" the Logical name for such a quality is the DIFFERENTIA=difference= characteristic. This is something joined to the essence.

4. A quality which belongs universally to the species, as that of "inebriating" to wine, without being its distinguishing quality, is termed a PROPERTY of it.

5. A quality which does not belong universally to a species, but is present only in some of the individuals which compose it, as that of being "sweet" to "wine," is termed an ACCIDENT.

A common term, we have seen, is so called from its expressing what is common to several things, and thence called also a "predicable," inasmuch as it can be affirmatively predicated in the same sense ("univocally") of certain other terms.

1. When you are asked concerning any individual thing, "What is it?" the answer you would give, if strictly correct, would be what is strictly called its SPECIES; as, "This is a pin,” "that is a pencil;" "this is wine." This predicable, namely, the species of any thing, is usually described in technical language as expressing its whole Essence, meaning the whole that can be expressed by a common term.

2. When the same question, "What is this?" is asked respecting a species, the term by which you answer is that predicable which is technically called the GENUS of that Species; as,