Practical logic

Preface

The little work here presented to the public, is an attempt to fill up a remarkable gap in the course of elementary treatises intended for youth. Among the interminable number of school books, there fe no one of a practical kind, expressly calculated for advancing pupils in the most important of ail attainments, — the art of just and accurate reasoning. The ordinary systems of logic do not answer the end, and are accordingly always left for the study of riper years. What is wanting, and what this manual attempts to supply, is a plan which may lead young persons to think and reason for themselves, may point out the common errors to which they are liable, unfold as far as necessary, that is, as far as their practical improvement requires, the nature of an argument, and explain the terms of art which they will have to use or understand. The plan laid down is the result of actual experience in teaching. The author, though

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VI PREFACE*

chiefly occupied as a lecturer on Elocution, is frequently required, particularly in ladies' schools, in some of the first of which, in and near London, he is the English master, to add to the Reading lesson some instruction in Composition ; and being conscious that accuracy of thought and reasoning ought to form the primary object of the exercises in this department, he has always been accustomed to call the attention of his pupils more closely, at first, to this point than to the niceties of style, lest the more important object should be overlooked and forgotten. But while the study table was loaded with books for their guidance in all that relates to grammar and diction, not one was at hand to clear the way immediately before them ; and their progress was therefore less certain and satisfactory than it would otherwise have seemed, because the faults were undefined, by avoiding which their improvement was estimated.

Such was the exigency that produced the following pages. The detail of the plan will be best understood by running the eye over the table of contents. If some parts of the second and third chapters, which attempt to develop the nature of an argument on philosophical, though it is hoped,

PREFACE. VII

plain principles, should be deemed too much for the comprehension of beginners in theme-writing, let it be remembered that these parts are not meant to be forced on the pupil's attention, till he feels a want of the information contained in them. On first using the book, the teacher and pupil had better seek for assistance in Chapter the fourth, where the method of writing Themes is explained, and plans for several Themes are laid down. The pupil should then proceed at once to try his own powers on easy subjects, and read Chapter the first to assist his practice, the teacher taking care, in correcting his exercises, to point out how far he has fallen into, or avoided the faults which are there described and exemplified. At length, through these means, he will obtain some insight into the nature of an argument, and he will then be competent to pursue the inquiries in the subsequent chapters, the teacher, at the same time, being careful to try the reality of his progress by the questions in the Appendix.

Though the book is intended chiefly for youth at school, the author presumes to think it may not be useless to many who have finished their early studies. They will smile, no doubt, at the rawness

Vlll PREFACE.

manifest in most of the examples, but the faults described are not less important to be guarded against, because the author has judged it best to illustrate them by instances taken from the themes of the younger among his pupils. Had he wished to give consequence to his little volume, he could easily have brought all his examples from works that have appeared in print. He is glad to avoid so invidious a course, particularly as perhaps some of his own pages might lay him open to recrimination.

50, Leicester Square, Feb, 20, 1823.

CONTENTS AND ANALYSIS,

Chapter I

THE 'COMMON FAULTS WHICH LEARNERS COMMIT IN WRITING THEMES DESCRIBED AND EXEMPLIFIED, VIZ.

Second General Fault, Confusion among the Thoughts •«....«. 3

Third General Fault, Want of Connexion among the Thoughts. . 8

Faults of Verbiage,

Fourth Fault, Begging the Question 12

Fifth Fault, Explaining a thing by itself .................... 13

Sixth Fault, Distinction without a Difference ......*.. 14

Faults from Confusion among the Thoughts.

Seventh Fault, Confounding different Senses of the same Expression ...» • •.. 15

Eighth Fault, Overloading a Sentence <, • • 16

Faults from want of Connexion among the Thoughts.

Ninth Fault, Proposing too much 19

Tenth Fault, Forgetting the Proposition .................... 20 x CONTENTS.

PAGE

Eleventh Fault, Discoursing short of the Proposition ........ 21

Twelfth Fault, Discoursing wide of the Proposition 24

Thirteenth Fault, Proving too little 26

Fourteenth Fault, Proving too much 28

CHAPTER II. CHAPTER in

ARGUMENTS AND THEIR SEVERAL KINDS EXPLAINED.

The Nature of an Argument 38 — 52

Names of Arguments derived from the Topics whence they are taken, viz,

/Definition • 52

Etymology 53

Species 55

Adjuncts •• 57

Antecedents • • »•... 58

Consequents idem

Internal, j r, c emcient ) . .

Cause, } i or a priori

( final 5

Effect, or a posteriori • ••«.••••. idem

Similitude • idem

s a fortiori -^ Comparison, < analogical > 60

v proportionate J Contraries 61

CONTENTS. xi

PAGE

c Testimonies 62

External. ^ Singular Examples idem

Names of Arguments derived from the Data on which they rest, viz.

Argumentum ad judicium 63

Argumentum ad hominem idem

Argumentum ad verecundiam, &c. 64

Names of Arguments derived from the Forms in which they are expressed, viz.

Syllogism 65

Enthymeme idem

Epichirema idem

Dilemma 66

Sorites, &c idem

The Difference between Hypothetical and Categorical, direct

and indirect Argument 67

Reductio ad absurdum idem

Chapter IV

ON THE METHOD OF WRITING THEMES, WITH EXAMPLES, AND PLANS FOR SEVERAL THEMES.

On the Method of writing Themes 69—82

Subjects for Themes 91, 92

Plans for Theses 92—98 xii CONTENTS.

Appendix

PAGE

1. Questions for examining the Pupil, adapted to the foregoing

Chapters • • 99

2. A few general Rules for Punctuation . , ..,»«*.•».«. 107

PRACTICAL LOGIC;

OR,

HINTS

TO

YOUNG THEME-WRITERS.

Chapter I

THE COMMON FAULTS WHICH LEARNERS COMMIT IN WRITING THEMES, DESCRIBED AND EXEMPLIFIED.

The word Theme properly means the subject of a discourse ; but the discourse itself, if merely an exercise in Composition, is also called a Theme.

A Theme may otherwise be described, as indeed it ought to be considered, an exercise in the art of thinking. In the earlier stages of education, the sole employment of learners is to collect, from others, materials for thinking: in writing themes, they are required to bring these materials into use by thinking for themselves. As to language, it should be considered only as the means

B

2 Verbiage.

or instrument of thinking * and of making the thoughts known outwardly. Unless viewed in this light, and employed solely for these purposes, the pupil sets out on a wrong principle, and no real improvement will be made. Hence the first fault to be laid down as necessary to be avoided, is the undermentioned :

FIRST FAULT TO BE AVOIDED.

Joining words and phrases together which seem, from their plausible sound and connexion, to convey a meaning, when, in reality, we have no clear thoughts on the subject to express. This forms what the French call, Verbiage,

A pupil who has read a great deal, but has not thought a great deal, will have his head very full of book phraseology, and very empty of ideas, and will be apt to put this cheat upon himself, and possibly upon some others, by a kind of jargon, of which the following may serve as a specimen.

ON EDUCATION.

The invaluable blessings of a refined Education, are so multifarious in their extent, and so incalculable in their number, that the understanding and the imagination are equally unable to comprehend the phenomena

* To assert that language is the instrument of thinking must not startle the young reader : without representative signs of some kind, we could never abstract or generalize. This doctrine will become clearer, as he advances.

Confusion among the Thoughts. S

involved in the boundless subject. Who indeed can justly appreciate the ineffable advantages which accrue to gifted individuals, ardent to develop the germs of scientific lore ? Still less can we discern the endless ramifications springing from that centre, of which Education is the heart and soul. Educational discipline exalts the faculties, animates the mind, improves the understanding, and, by throwing a divine light on the abstract operations of human intellect, gives a new grace* to the whole character. Through the instrumentality of the influence which Education alone can impart, we are lifted to another sphere. In short, Education is the first of things, the master key, the universal good, and we are bound at once to reverence its authority, and apply to its pure fountain for mental delight, and intellectual improvement.

SECOND FAULT TO BE AVOIDED.

Confusion among the thoughts ; arising from the absence of all distinction and division.

However confused, incorrectly expressed, and inelegant, a pupil's Exercise may be, yet if it exhibit the least evidence of some definite notions on the subject suggested, the work of correction may commence, and gradual improvement may thenceforward be expected :— it will be the teacher's business to show, in every exercise, how the thoughts may be better arranged, and more correctly expressed ; and the pupil, by constant attention to these corrections, will grow into method and perspicuity. But with an Exercise like the example b2

4 Confusion among the Thoughts.

just given, nothing can be done : it is not a beginner's Exercise in the art of thinking, but in a very different art ; and the teacher, to do his pupil justice, must run the correcting pen through the whole, and require him to make altogether a new beginning.

Possibly the learner, before every Exercise, will require to be assisted to a few thoughts ; nor must it be imagined, even if he is indebted to his teacher for every sentiment he expresses, that they are the less his own: for are not all his sentiments acquired ? — how, and at what time, is of little moment, if it be certain that his mind completely entertains and acknowledges them. But between two pupils thus assisted by their teacher, one of whom makes his Theme an Exercise of thought, and the other, an Exercise of words, there will be this difference, — the former will forget many of the expressions, but will carry away the meaning, which he will embody in more homely, and less correct language of his own ; the latter will carry away all the best sounding words and phrases, with which he will make an incoherent jumble, wearing much of the outward form of what the teacher suggested, without any of the spirit. An Exercise of this kind affords no promise ; — it is altogether an erroneous attempt; and the teacher can do nothing but send his pupil back, perhaps with new assistance, to make another trial : but an Exercise of the other kind, however meagre

Confusion among the Thoughts. 5

and deficient, may be accepted for a beginning : improvement will come with practice. The following is an example of a very humble attempt, but still of one that affords some promise.

ON EDUCATION.

Education is certainly one of the most important things which belong to man, and the most useful and essential of any, if we reflect what a wild savage race we should be, if it were not for this inestimable blessing, and how very fortunate they ought to think themselves who have parents both able and willing to be at the expense of it, without which we should not know the Author of our existence to whom we are indebted for all our blessings and comforts, and we should not be able to provide for ourselves, for it is not the same with us as it is with birds, which instinct teaches to provide for themselves when they leave the nest of their parents, instead of which we are not only made agreeable in society, but if we make a proper use of it, it is the source of all happiness, and therefore since we are sensible of its worth, let us who possess it think ourselves unspeakably happy, and never think it too much trouble to obtain, for surely it is the least we can do for such a valuable benefit.

This production is an attempt to form a connected discourse out of a number of remarks, which, for the purpose, are indiscriminately huddled together by an undue use of conjunctions, relatives, and other uniting particles. And this may serve as a specimen of what will gene-

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6 Confusion among the Thoughts.

rally be the first essay of every young student. As yet, it is evident he knows nothing of the art of Composition ; for Composition means arrangement, and of this his remarks are altogether destitute. It is in seeing his Theme corrected that he gets the first insight into his business; and therefore the nature of the corrections must be carefully studied. Let him observe, then, that all the remarks he has made do not come under the same description ; for some might come under this head — On the importance of Education ; and some under this — On our duty as young students ; and thus the Theme separates into two smaller Themes, to be signified by a division or break forming what are called Paragraphs # . And again, let him consider, that if the remarks in each of these paragraphs explain, illustrate, and enforce each other, there is no necessity for any closer connection ; and instead of huddling them together, he ought to keep them separate and distinct, in order that every remark may be clearly apprehended in its turn. For this purpose, let him use the period or full stop as often as any assertion, or any single argument, or any remark of whatever kind, seems of consequence enough to stand by itself; and where the connexion seems too close for a period, let him use a colon or semi-

* Chapter III. on the Method of writing Themes, must be referred to for further information on this point.

Confusion among the Thoughts. 7

colon, and the comma only where the construction of the sentence evidently forbids any higher stop # . Thus by division and subdivision, with a few minor corrections, this first Exercise will be moulded into the following shape.

ON EDUCATION.

Education is the most important and essential concern of man. For let us reflect what a wild, savage creature he would be, without this inestimable blessing. He would not know the Author of his existence, to whom he is indebted for all his comforts. He would not be able to provide for himself. For it is not the same with man as it is with birds : they know, almost entirely by instinct, how to provide for themselves ; but all knowledge necessary to man, comes by Education. It is Education which lifts him from his helpless state, makes him an agreeable member of society, and prepares him for all happiness.

Since, then, education is so important, let us to whom it is offered think ourselves unspeakably happy, and never imagine we can employ too much pains to secure all its advantages. Let us reflect how very fortunate we are in having parents both able and willing to be at the expense of books and instructors ; and let us show our gratitude by our willingness to learn, which is surely the least return we can make for benefits so valuable.

* For further directions respecting punctuation, consult the general rules in the Appendix.

B 4

3 Want of Connexion among the Thoughts.

THIRD FAULT TO BE AVOIDED.

Want of Connexion among the Thoughts* From one extreme, it is not unlikely that the learner may run into another. Warned by the confusion which appeared in his first attempt, and aiming at the greater distinctness of the corrected copy, he will perhaps, at the next attempt, produce an Exercise formed of sentences after the following manner :

ON FRIENDSHIP.

Friendship is a subject which has often employed the pen of the moralist. We all feel that Friendship is necessary to our happiness. Many persons pretend to be influenced by Friendship, who are incapable of so noble a sentiment. Without a friend, the world &c. &c.

Sentences of this kind do not form a theme, because, though they all relate to the same subject, they are not parts of the same train of thoughts : they are entirely independent of each other, and ought indeed not to be written down in immediate succession, but with breaks in the manner of paragraphs, thus :

Friendship is a subject which has often employed the pen of the moralist.

We all feel that Friendship is necessary to our happiness.

Many persons pretend to be influenced by Friendship, who are incapable of so noble a sentiment.

Want of Connexion among the Thoughts. 9

This is the way to write maxims or proverbs, but a theme must be managed very differently. We must not start from one remark to another which has no immediate relation to it, but consider how the proposition we set out with, can be enforced or supported by remarks tending to the same purpose, till nothing more seems needful to be said upon that branch of the subject # . And where a remark appears to be destitute of a sufficient purpose, we must either reject it altogether, or turn it to a purpose by the remarks that follow it : — the first of the foregoing remarks is an instance, — "Friendship is a subject that has often employed the pen of the moralist." It seems hardly worth while to make this remark for the sake of itself, and therefore we expect some following remarks to define its purpose : for example :

Friendship is a subject which has so often employed the pen of the moralist^ that the few thoughts it may suggest to my mind, cannot be either novel or striking. Yet my remarks, though trite, may deserve some attention, because the subject itself is of the highest importance.

Thus amplified, the sentence forms a proper introductory paragraph. The next sentence may now be taken, and followed up thus :

We all feel that Friendship is necessary to our happi-

* The invention of arguments is treated of in the latter part of Chapter III.

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10 Want of Connexion among the Thoughts.

ness. Framed for society, we stand in continual need of assistance, support, advice, and sympathy. But the coldness of the world, and even the indifference of our own hearts to all except a few by whom we are surrounded, soon teach us, that, without sincere friends, we may look for these good offices in vain. Therefore we always flatter ourselves we possess friends, though there are many who pass through life unendeared to a single heart, and who are never served or assisted but through motives of interest or of fear.

This paragraph being completed, we may take the next sentence as the ground of another :

Many persons pretend to be influenced by Friendship, who are incapable of so noble a sentiment. The selfish cannot feel it: — they will connect themselves with others to reap some immediate advantage, but they are ever strangers to that regard which frames to itself a happiness out of the happiness of others : all their views are of profit or of pleasure solely to themselves. Yet none are more ready than the selfish to give the colouring of friendship to all their actions ; because they know this to be the most likely means of securing the return of greater benefits than they yield.

It is to be observed* that not only the sentences belonging to the same paragraph should seem to grow out of each other, but the paragraphs themselves should have some kind of relation, more than that of merely treating of the same subject. Therefore, though the foregoing paragraph may not be liable to any objection in itself, yet when placed 5

Want of Connexion among the Thoughts, beside the other, it appears to be defective by not being consequent upon what preceded it. This fault may be corrected by drawing such a consequence from the second paragraph as may serve for the ground of the third : for example :

As Friendship is so important towards the happiness of life, we cannot be too careful in our choice of friends, lest we place a reliance on those who will desert and betray us in the hour of difficulty and distress. For alas ! many persons pretend to be influenced &c.

A short sentence may likewise be added to the paragraph, to wind it up in correspondence with its beginning ; as,

Against such pretended friendship, let confiding ge-* nerosity be ever on its guard.

Thus it appears, that a Theme ought to be free from verbiage — that the parts ought to be properly arranged — and that the thoughts should flow from, and support each other. Almost every fault which the learner will commit, he will find to be a deviation from one or the other of these three rules ; and therefore the faults which are hereafter noted, are not to be considered distinct from those already pointed out, but rather as instances of particular modes in which the general rules are violated.

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*2 Begging the Question.

FOURTH FAULT TO BE AVOIDED.

Begging the Question,

In endeavouring to follow up a proposition by remarks that agree with, and support it, the learner must well consider the nature of each remark, and use no other connecting words than such as are suitable to its purport ; otherwise the sentences so connected will be verbiage : for instance :

Pride is odious, because it is disliked by all : for it produces universal hatred.

Here the words following because and for, pretend to be a reason for, and a proof of, what is previously asserted, and they only say the same thing over again in a different manner. Standing thus, they are verbiage ; for they are meant as reasons, and perhaps sound as such, without being so in reality. And as the writer begs that to be allowed for a proof of the question, which is in fact the question itself, he is said to beg the question. There would not be the same cause of objection, if no pretence were made of giving a reason : as,

Pride is odious ; — it is disliked by all ; — it produces universal hatred.

To repeat the same proposition in different words may occasionally be proper for the sake of greater clearness, or of adding circumstances at first omitted ; and sometimes a proposition requires only this forcible statement, in order to be acknow-

Explaining a thing by itself. 1 3

ledged. But when a reason or a proof is proposed to be given, the writer must be at the pains of seeking one : as

Pride is odious, because our self-love makes us feel it as an injury done to our own importance.

Or

Pride is odious ; for all persons shun the society of the proud.

FIFTH FAULT TO BE AVOIDED.

Explaining a thing by itself : that is, using, in the explanation of a thing, the same word, or a word having the same meaning, as that which stands for the thing to be explained.

This is a fault of the same nature as the last ; but as it is, in general, more easily corrected, and frequently arises merely from inadvertence, a separate notice of it may be proper. The following will be a sufficient example.

Justice regards both magistrates and private individuals. The former show themselves to be influenced by it, when they make an equitable distribution of rewards and punishments ; the latter, when they are sincere in their words, and just in their dealings.

The words equitable and just cannot serve to explain justice ; for having the same meaning, they do but repeat the thing which is to be explained. Let impartial be substituted for the former word,

14 Distinction without a Difference.

and honest for the latter, and the explanation will agree with the writer's intention.

SIXTH FAULT TO BE AVOIDED.

Distinction without a difference.

Against this common species of verbiage, one or two examples will be a sufficient warning.

Example 1.

L propose to consider, first, the evils which arise from Procrastination, and then, the miseries we should avoid by performing all our duties at their proper time and place.

The writer, if he really means different things, must mean " first, the evils of Procrastination, and then the benefits of performing" &c.

Example 2.

Books are the receptacles of knowledge, and the depositories in which the collected wisdom of ages is treasured up.

Docility is a readiness to receive instruction, and a willing obedience to those who teach.

In each of these examples, the latter part of the sentence does but explain the former, as a noun in apposition explains its fellow noun ; and therefore the conjunction and, which signifies addition, should be omitted : as

Confounding different Senses of the same Expression. 15

Books are the receptacles of knowledge — the depositories &c.

Docility is a readiness to receive instruction — a willing obedience &c.

And as adding what is no addition always amounts to a distinction without a difference, so likewise does disjoining what is not distinct ; as

Example 4.

To be neither merciful nor compassionate is unsuitable to the nature of man.

Here the writer ought to say " Not to be compassionate is" &c.

The fault opposite to that last noted is, a difference without a distinction. This is not a fault of verbiage, but is the second general fault, described and exemplified at pages 3, 4, 5, &c. Of this the seventh and eighth faults which follow, are particular instances; in the same manner as the fourth, fifth, and sixth faults just noted, were particular instances of the first general fault.

SEVENTH FAULT TO BE AVOIDED.

Confounding different senses of the same expression* An instance of this error occurs in the following remarks :

To write well is an accomplishment of the first importance, because we form an immediate judgment of a

16 Overloading a Sentence.

person's education from the manner in which he writes. If we receive from any one a letter scarcely legible, scrawled rather than written, we hardly think well of the writer's education, though perhaps the sentiments may be tolerably expressed. But if the language is ungrammatical, and all the sentences confused ; in short, if there appears a total deficiency of skill in the art of writing, we immediately conclude that the person is altogether ignorant and illiterate.

Here bad writing in the sense of bad penmanship, and in the very different sense of bad composition, are confounded together. The whole may be corrected thus :

To write a fair hand is an accomplishment of much importance, because we often form an immediate judgment of a person's other acquirements from the hand he writes. But it is of much more importance to obtain a correct and graceful style of expression. The one is a manual, the other, a mental art. If we receive from any one a letter scarcely legible, scrawled rather than written, we hardly think well of the writer's education, though perhaps the sentiments may be tolerably expressed. But if the language is ungrammatical, and the sentences confused ; in short, if there appears a total deficiency of skill in the art of composition, we &c.

EIGHTH FAULT TO BE AVOIDED.

Overloading a Sentence : that is, mingling foreign matter with what is the proper business of it.

Three instances shall be given of this fault i

Overloading a Sentence. 1 7

Courage leads us to face danger without fear ; Fortitude, to bear calamity without complaining, and is a virtue all ought to possess : for being, as we all are, born to trouble, afflictions of some kind must fall to our lot.

The proper business of the former part of this sentence, was to define fortitude as opposed to courage, and that business being completed, the sentence should have ended, namely at the word complaining. What follows should be not only in a different sentence, but should begin a new paragraph with the word Fortitude repeated as the nominative to the verb is. For it appears that the writer having made his way clear by defining his subject, is about to consider its necessity, &c.

Example 2.

The high-born, the rich, and the beautiful, are peculiarly exposed to Flattery; and the sweet incense is offered to them in abundance, by those whom all good men justly abhor for their deceitful servility.

This sentence resembles a person who, by trying to do two things at a time, fails in both. The writer purposes to show the dangers arising from flattery which attend birth, wealth, and beauty; and also to show the baseness of flatterers. These two purposes should have been kept distinct ; they should not have been attempted even in the same

18 Overloading a Sentence.

paragraph, much less in the same sentence. To correct the example, we must suppose the two parts of the sentence to stand in different divisions of the theme :