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person to whom we may direct our attention, may be considered either in a political point of view, and accordingly referred to the class of Merchant, Farmer, Lawyer, &c. as the case may be; or physiologically, as Negro, or White-man; or theologically, as Pagan or Christian, Papist or Protestant; or geographically, as European, American, &c. &c. And so, in respect of anything else that may be the subject of our reasoning: we arbitrarily fix upon and abstract that point which is essential to the purpose in hand; so that the same object Different abmay be referred to various different classes, from the according to the occasion. Not, of course, that we are allowed to refer anything to a class to which it does not really belong; which would be pretending to abstract from it something that was no part of it; but that we arbitrarily fix on any part of it which we choose to abstract from the rest.
It is important to notice this, because men are often disposed to consider each object as really and properly belonging to some one class alone,* from their having been accustomed, in the course of their own pursuits, to consider, in one point of view only, things which may with equal propriety be considered in other points of view also: i. e. referred to various
* See the subjoined Dissertation, Book IV. Chap. v.
CHAP. I.-Of the Operations of the Mind and
Operations of the mind.
THERE are three operations of the mind which are immediately concerned in argument; 1st. Simple Apprehension; 2d. Judgment; 3d. Discourse or Reasoning. *
1st. Simple-apprehension is the notion (or conception) of any object in the mind, analogous to the perception of the senses. It is either Incomplex or Complex: Incomplex Apprehension is of one object, or of several without any relation being perceived between
* Logical writers have in general begun by laying down that there are, in all, three operations of the mind : (in universum tres) an assertion by no means incontrovertible, and which, if admitted, is nothing to the present purpose ; our business is with argumentation, and the operations of the mind implied in that; what others there may be, or whether any, are irrelevant questions.
The opening of a treatise with a statement respecting the operations of the mind universally, tends to foster the prevailing error (from which probably the minds of the writers were not exempt) of supposing that Logic professes to teach “ the use of the mental faculties in general;" - the "right use of reason,” according to Watts.
them, as of “ a man,' a horse,” “ cards:” complex is of several with such a relation, as of “a man on horseback," "a pack of cards.”
2d. Judgment is the comparing together in Judgment. the mind two of the notions (or ideas) which are the objects of Apprehension, whether complex or incomplex, and pronouncing that they agree or disagree with each other: (or that one of them belongs or does not belong to the other.) Judgment, therefore, is either affirmative or negative.
3d. Reasoning (or discourse) is the act of Discourse. proceeding from one judgment, to another founded upon that one, (or the result of it.)
§ 2. Language affords the signs by which these Language. operations of the mind are expressed and communicated. An act of apprehension expressed in language, is called a term; an act of judgment, a proposition ; an act of reasoning, an argument ; (which, when regularly expressed is a syllogism ;) as e.g.
“Every dispensation of Providence is beneficial;
Afflictions are dispensations of Providence,
is a Syllogism; (the act of reasoning being v indicated by the word “ therefore,") it consists
of three propositions, each of which has
(necessarily) two terms, as “ beneficial,” “ dispensations of Providence,” &c.*
Language is employed for various purposes: Sylogisms. e.g. the province of an historian is to convey
information ; of an orator, to persuade, &c. Logic is concerned with it only when employed for the purpose of reasoning, (i. e. in order to convince ;) and whereas, in reasoning, terms are liable to be indistinct, (i. e. without any clear, determinate meaning,) propositions to be false, and arguments inconclusive, Logic undertakes directly and completely to guard against this last defect, and, incidentally and in a certain degree against the others, as far as can be done by the proper use of language : it is, therefore, (when regarded as an artt) “ the Art of
* In introducing the mention of language previously to the definition of Logic, I have departed from established practice, in order that it may be clearly understood, that Logic is entirely conversant about language: a truth which most writers on the subject, if indeed they were fully aware of it themselves, have certainly not taken due care to impress on their readers. Aldrich's definition of Logic, for instance, does not give any hint of this.
* It is to be observed, however, that as a science is conversant about knowledge only, an art is the application of knowledge to practice : hence Logic (as well as any other system of knowledge) becomes, when applied to practice, an art ; while confined to the theory of reasoning, it is strictly a science: and it is as such that it occupies the higher place in point of dignity, since it professes to develop some of the most interesting and curious intellectual phenomena. It is surely strange, therefore, to find in a
employing language properly for the purpose of Reasoning.” Its importance no one can rightly estimate who has not long and attentively considered how much our thoughts are influenced by expressions, and how much error, perplexity, and labour, are occasioned by a faulty use of language. A
A syllogism being, as aforesaid, resolvable into three propositions, and each proposition containing two terms; of these terms, that which is spoken of is called the subject ; that which is said of it, the predicate; and these two are called the terms (or extremes) because, logically, the Subject is placed first, and the Predicate last: and, in the middle, the Copula, which indicates the act of judgment, as by it the Predicate is affirmed or denied of the Subject. The Copula must be either is or is NOT, the substantive verb being the only verb recognised by Logic: all others are resolvable, by means of the verb, “to be," and a participle or adjective : e.g. “the Romans conquered :” the word conquered is both copula and predicate, being equivalent to
to “ were (Cop.) victorious” (Pred.)* treatise on Logic, a distinct dissertation to prove that it is an Art, and not a Science!
* It is proper to observe, that the copula, as such, has no relation to time; but expresses merely the agreement or disagreement of two given terms: hence, if any other tense of the substantive verb, besides the present, is used,