purely logical must be still more subject to the choice or arbitrary determination of the thinker. In forming these, he is under no more than a prudential restraint; as, for instance, the custom of language, which ought to prevent him from defining a word quite apart from its usual meaning. One thing he has always to remember, that whatever limitation he chooses to give to the meaning of a word, to that he should strictly adhere in his subsequent development. Suppose, for instance, that he has defined (Pride to be inordinate selfesteem,―he could not, under such a definition, justly propose, in any branch of his development, to treat of a proper or decent pride; for the very purpose is contradictory. To accomplish the purpose, his original, or some secondary definition, must assign a less limited meaning to the subject, as, for instance, by calling it self-esteem, simply; and then treating of it under the heads of an improper and a proper self-esteem.

First Note to Chapter III.

It may assist the student to the better understanding and application of what precedes, to quote, however we may have anticipated them, the following rules and cautions from Dr. Whately's Logic: "First, the definition must be adequate; that is, neither too extensive nor too narrow for the thing defined: for example, to define fish an animal that lives in the water, would be too extensive, because many insects and other creatures live in the water :-to define it an animal that has an air-bladder, would be too narrow, because many fish are without any. Or again, if in a definition of money, you should specify its being made of metal, that would be too narrow, as excluding the shells used as money in some parts of Africa: if again you should define it as an article of value given in exchange for something else, that would be too wide, as it would include things exchanged by barter. And observe, that such a defect in a definition cannot be remedied by making an arbitrary exception: if, for instance, a person were to give such a definition of capital as should include land, without meaning to have included it, and should then propose to remedy the fault by saying, that capital is any property of such and such a description EXCEPT LAND. Secondly, the definition inust be in itself plainer than the thing defined, else it would not explain it :-in itself plainer, that is, generally; because, to some particular person, the term defined may happen to be even more familiar and better understood, than the language of the definition. And thirdly, (though this rule may be considered as included in the rule just given,) the definition should be couched in a convenient number of appropriate words. Figurative words are opposed to appropriate, and are apt to produce ambiguity or indistinctness too great brevity may occasion obscurity; and too great prolixity, confusion."" Tautology, which is a distinct fault from prolixity or verbosity, must also be avoided, that is, tautology which consists in in

serting too much, not in mere words, but in sense; not so as too much to narrow the definition (in opposition to Rule first,) by excluding some things which belong to the class of the thing defined, but only so as to state something which has been already implied. Thus, to define a parallelogram, a four-sided figure whose opposite sides are parallel AND EQUAL, would be tautological; because, though it is true that such a figure, and such alone, is a parallelogram, the equality of the sides is implied in their being parallel, and may be proved from it. Now the insertion of the words and equal, leaves, and indeed leads, a reader to suppose that there may be a four-sided figure whose opposite sides are parallel, but not equal. Though therefore such a definition asserts nothing false, it leads to a supposition of what is false; and consequently is to be regarded as an incorrect definition." The effect may be further illustrated by the following examples. "If it be laid down that he who breaks into an empty house shall receive a certain punishment, it may be inferred that this punishment will not be incurred by breaking into an inhabited house :-if it be called a crime for people to violate the property of a humane landlord who lives among them, it may perhaps be inferred that it is no crime to violate the property of a landlord who is not humane, or is an absentee."

Second Note to Chapter III.

Connected with the laws of definition, and indeed involved in them, is the fixing of preliminary conditions, at least in the mind, before we enter on a dispute or discussion. It should be settled, for instance, what is the ground of dispute :-is it a real or verbal question, that is, a question concerning facts, or a question concerning the application of a word? A dispute otherwise interminable, may often be cut short if not adjusted, by the application of this test. Two persons are disputing whether A. B. was a man of genius :-" Are you," it may be said by one of them, " are you agreed with me that he was capable of such and such productions; if so, it is a question about the application of a word, and now let us see in what way custom authorizes the use of the word, and what sense agrees with our present meaning.' Or suppose the parties use the word in exactly the same sense; then the dispute turns on facts or the character of the facts; to ascertain which, recourse must be had to inquiry, comparison, and general estimation. Further; the logician should be aware that on many questions which are given out for the express purpose of provoking discussion, a sensible person would express no opinion unless he were permitted to qualify it. Thus, for instance, the often mooted question: Is a public or private education preferable? This, as a general question, cannot be rationally answered:-we ought to know exactly what the education is, which, under each denomination, is proposed to be given, as well as the disposition of the person who is to be subjected to it, and his ulterior prospects in life. Thus limited, the question would present itself in a very different shape, and probably leave room for little or no difference of opinion.-In the wars which closed with the Pacification of Paris in 1815, was Great Britain more indebted to her army or her navy? Such a question in an assembly composed of the two different interests, would probably have produced, some few years ago, a very animated discussion; but it is one which, instead of discussing, it would be wise to

object to altogether, on the ground of its being impossible to be proved; that the operations of each service for which credit would be assumed, did not arise out of, and take their character from, the existence of the rival service--the question is nearly like such a one as this,-Is the heart or the head more useful to the rest of the body? We might indeed reasonably ask, whether Great Britain should seek to be a great naval, or a great military power? Such a question would permit a decision on rational grounds; but in proportion as we become rational, we leave less room for contention, and the other question would probably be preferred by those who propose subjects expressly to provoke discussion.-Is the decline of nations more owing to the misconduct of governments, or the degeneracy of the people? Here two separate causes are assumed, before it has been established that they act separately. We might as well ask, whether the decline of the bucket into the well is more owing to the rope or the wheel? It would indeed be reasonable to inquire, whether wrong principles and practice in government do not produce degeneracy in the people?-and, whether degeneracy in the people, does not leave little chance of a good government to reclaim them? The determination of these inquiries, which would be attended with little or no difference of opinion, would show that there is no rational ground for the alternative proposed in the previous question.-Is a convulsive revolution, such as we have of late so often witnessed on the continent, mischievous or beneficial to a nation? A sensible reasoner would affirm neither side of the question, unless permitted to qualify, and then he would affirm both: it is mischievous at the time; it is likely to be beneficial in some uncertain number of years to come. We thus walk aside from the snare, for which, it may be, the question was put. Had the answer affirmed such a revolution to be beneficial, it would have opened the means of rhetorical delusion specified in the last Chapter, (Section 33.) As it is, the answers are quite innocent; the one affirms an experimented fact; the other permits no practical inference; since, though it is true that a man may get a new and a better house by being burned out of an old one, we cannot rationally act upon this fact, and set a house on fire to the imminent danger of the inmates and the neighbourhood whenever a new one is wanted.

CHAPTER IV.

DEDUCTIVE LOGIC.

1. Deductive logic is the art of developing in words, and making special, for one's own conviction and satisfaction, the knowledge obtained by the inductive process. It differs from Rhetoric by stopping short at the object stated. Nevertheless, as Logic ought to be exercised so as to prepare for Rhetoric, every development of deductive logic must be considered imperfect, unless, while it convinces and satisfies oneself, it is also fitted to convince and satisfy all, who have the same previous knowledge.

THEORY OF DEDUCTIVE LOGIC.

2. We have seen that, in the inductive process, every act of the understanding includes three things, the thing known, the thing by which it is known, and the knowledge gained. Being gained, the knowledge remains abstract from the things, not indeed ever present to consciousness, but revivable upon occasions that require it, by the presence of real or of ideal things, or by means of a sign audible or visible. But when the knowledge is revived by its proper occasion, it does not always bring with it all the things which suggested it; and we have to develop these things by that conscious effort which we call thinking. This is, in other words, to go back to the steps (not exactly, which would scarcely be possible, but virtually, to the steps) which led to our knowledge: and such development is the practice of deductive logic; which development never includes, in strict theory, more than we already know. Thus, for instance, we may meet with some instance of kingly magnificence which awes our thoughts, so that we understand, for a moment, such condition of man as something different from the ordinary lot of humanity; but considering afterwards, as a part of our knowledge already acquired, that a king is but a man, we shall conclude that kings are not exempted from the lot of other men, but, like them, are mortal. The development of such knowledge may be expressed in words by a single proposition, namely, Kings, who are but men, are mortal." Or it may be expressed in three propositions, which represent the three things that originally constituted our knowledge: namely, 1. " Every man is mortal: 2. Every king is a man: 3. Therefore, every king is mortal." When we develop our knowledge in this manner, the three propositions are a syllogism. When we develop it in any other way which forces assent from a person possessed of the pre-supposed knowledge, the syllogism is virtually included in the expression; because the three things which the syllogism represents, are included in every act of the understanding. Hence, the syllogism is properly resorted to in all cases of doubt or difficulty, for the purpose of testing the knowledge gained, with relation to the conclusion which it necessarily includes.

66

Note to Section 2.

Our Syllogism is the informal Syllogism, by which is meant the Syllogism that makes no use of the doctrine of comparison between extremes and middle terms, which belong only to the doctrine of the formal syllogism of Aristotle. The syllogism given as our example above, happens to exhibit those terms in the construction of the several propositions; but this is accidental to our syllogism, and not essential or important. In our doctrine, each premise of the syllogism is one expression with one meaning; and, in the instance above, is the statement, in each, of a known truth or fact. But these facts are no sooner stated in connection, than they inevitably suggest the conclusion which is expressed by the third; and the whole of them are now one expression with one meaning. To ask why they are so, or to take in hand a demonstration of what is thus attained, is a question, and a proceeding, as absurd as it would be to ask why a rose is fragrant, and to set about a verbal demonstration that it is so. Accordingly, with men of sense and education, but not so educated as to be trammelled by scholastic logic, the syllogism in actual use, is the informal syllogism; and to this they have recourse, when, in the inductive process, not being quite satisfied with the grounds on which they have come to some inference, they deduce the process in a syllogism, that so the grounds and the conclusion (inevitable in the deduction) may be clearly set forth, and the defect, if any, may be seen; which fault will always be found in the premises, and never in the conclusion.

But say the Aristotelians,—that is, they who are trammelled by scholastic logic,- -we find in the practice of reducing all syllogisms to the demonstration of extremes and middle term, a wonderful power in sharpening the intellect. It may be so riddles, charades, and conundrums have this power also. But is it an exercise which sharpens the intellect for the high practical purposes of life? May not a person acquire great skill in the reduction of reasoning to the Aristotelian formulas, without any benefit, nay even with prejudice, to the natural powers of the understanding exerted for the ends just alluded to? He who makes use of a complicated instrument to effect that which nature has fitted him to do with his naked hand, may possibly fail in using the instrument, though he could not fail in using the natural means. We reserve our proofs of what is here suggested only as possible, to another opportunity. If we shall be able to show that Dr. Whately himself is guilty of a gross fallacy, that of the circle, in endeavouring to establish the claims of the Aristotelian syllogism, the cause of the error must be set down, in him, not to the want of great natural judgement, which Dr. Whately, of all men, cannot be accused of, but to some defect in the employment of his instrumental means of coming at his conclusion. (See the next Chapter, Section 9.)

There is an enormous delusion in the doctrine of the Aristotelian syllogism, which may be taken notice of before concluding this note. In this doctrine it is pretended that the reasoning process can be exhibited distinct from the subject-matter of reasoning. What we affirm, (and the affirmation, we presume, carries conviction along with it,) is, that where there is no subject-matter to be understood, there can be nothing under