The theory and practice of argumentation and debate

All persons of average intelligence and education are able to distinguish an obviously sound argument from an obviously false argument. No knowledge of argumentation or logic is necessary to enable such persons to perceive the truth of one or the falsity of the other. However, the line which separates the true from the false, or the sound from the unsound, is not always clearly marked. In fact most arguments involve a consideration of so many factors that their truth or falsity is very difficult to determine. It is for this reason that we must study the various theoretical forms in which an argument may be presented.

I. The application of processes of reasoning to argumentation.

Logic deals with the formal process of reasoning. It tests the validity of a reasoning process by applying certain principles which will reveal its strength or weakness. It is not essential to know the science of logic in order to reason or to argue well. Many of our most profound thinkers have possessed only a superficial knowledge of that subject. A knowledge of the forms of reasoning which logic considers, or of the names applied to them, is by no means indispensable to an intelligent argument or debate. Nevertheless, an exact knowledge of logical processes of reasoning as applied to the construction of arguments is absolutely indispensable to him who would become master of the Art of Argumentation and Debate.

There are two uses to which the debater must put these correct processes of reasoning. In the first place, he must use them to test the validity of his own arguments. In the second place, he must use them to test the validity of his opponents’ arguments. Both of these uses will suggest to the mind of the student the importance of the application of processes of reasoning to argumentation.

An argument is seldom presented in such a form that it is possible to apply logical reasoning processes to it as it stands. Usually some parts are omitted and others are expanded or modified for the purpose of greater effect in persuasion. The student must therefore grasp the essential parts of his argument before he can arrange them in the formal manner which logic demands. This very exercise of cutting up a discussion into parts for the purpose of determining whether it is rightly constructed is a mental exercise of unusual value. Furthermore, it reveals any weak places in the argument and shows where it must be made strong if it is to be effective. In like manner the debater is able to apply the same processes to the arguments of his opponents to show their weaknesses and enable him to direct his efforts toward these vulnerable points.

II. Inductive reasoning.

Inductive reasoning is the process by which we arrive at a general conclusion through the observation of concrete particulars. I have read Treasure Island and I found it interesting. Moreover, I have read Kidnapped, David Balfour, Prince Otto, and St. Ives, all of which were interesting to me. All of these books were written by Robert Louis Stevenson, and after I had read them I arrived at the general conclusion that all books written by Robert Louis Stevenson were interesting. I made use of this conclusion by searching in the library for other books by this same author, for I felt sure that if I could find another of his books it would be interesting. However, we are not now concerned with the uses to be made of this process of reasoning, but rather with its exact form. The process by which I arrived at the conclusion that all of Stevenson’s works are interesting is a fair example of inductive reasoning. I had five specific instances all pointing to the same conclusion. I had observed five of Stevenson’s books and I reached a conclusion regarding all of them. The conclusion included those which I had not read as well as those which I had read. This process conforms to our definition that inductive reasoning is the process by which we arrive at a general conclusion through the observation of concrete particulars.

In this way we arrive at many conclusions upon which we rely in our daily life. We go to a certain place at ten minutes past the hour for the purpose of boarding a street car which will take us to the city. We do this because for many months we have been accustomed to go to this same place at this particular time and there we have always found a street car which took us to the city. Each one of the instances in which we have done this is a concrete particular tending to support the general conclusion that if we go to a certain place at a certain time we shall find a car which will take us to the city.

A further investigation of this process of inductive reasoning reveals the fact that it may be divided into two sharply defined classes, (1) perfect inductions, and (2) imperfect inductions. A perfect induction is one in which all the particular instances upon which a conclusion is based can be examined directly. For example, if I am aware that each one of the twenty men who are taking this course in Argumentation expect to be civil engineers I may safely state the general conclusion that “All the men who are taking this course in Argumentation expect to be civil engineers.” This is a perfect induction, because I have included in the conclusion only those men who are taking this course; there are only twenty men and investigation has shown that each of them expects to be a civil engineer. Therefore, it is plain that there can be no opportunity for error. Every particular instance relied upon can be accounted for and no instance outside of these is brought within the conclusion. The induction is therefore perfect.

An imperfect induction is one in which the conclusion extends beyond the concrete specific instances upon which it is based. The examples already given regarding Stevenson’s novels and the street car are imperfect inductions. I have not read all of Stevenson’s novels and I may yet find one that is not interesting to me. Regarding the induction about the street car, it is sufficient to note that if the car were late or failed to appear at all, the conclusion would be of no value in that specific instance. Likewise I may state the general inductive conclusion that all roses are fragrant. I base this conclusion upon a great number of specific instances. The rose that I plucked yesterday was fragrant; those which I observed in the conservatory last month were fragrant; the roses which bloom in my door-yard each summer are fragrant; all the roses that I have known since I was old enough to notice such matters have been fragrant. Upon this great number of specific instances I base my inductive conclusion. It will be observed, however, that my conclusion is not confined to the roses which I have seen but that it extends beyond and includes all roses of every kind everywhere. It is therefore an imperfect induction. As it stands it would be impossible to make this induction a perfect one, because it would be an impossible task to examine every rose in the world. The only way in which the induction can be made perfect is to restrict the conclusion to cover only the specific instances upon which it is based. The conclusion would then be, “All the roses to which I have ever given attention were fragrant.”

But it may not suit our purpose thus to restrict the conclusion. We may wish to make use of it in its broad general significance. Every day we are compelled to act upon imperfect inductions, as in the case of the street car. In such cases we must resort to certain rules or tests whereby we can determine the probability of the truth of the imperfect induction. We shall consider these rules or tests after we have discussed the application of inductive reasoning to inductive argument.

III. The application of inductive reasoning to inductive argument.

We have seen the nature of the process of induction and have observed the distinction between the perfect and the imperfect. Let us now consider the application of the inductive process to arguments. The occurrence of this process in all argumentative discourse is frequent. A simple illustration of its application is furnished in connection with the proposition “Resolved, that the Federal Government should levy an income tax.” The affirmative in the course of its investigation finds that this tax has proved practicable in Switzerland, Germany, France, and England. Further investigation discloses the fact that these are the only countries in which this particular form of taxation has been adopted. From these particular instances, namely,—Switzerland, Germany, France, and England, the general inductive conclusion may be drawn that “The income tax has proved practicable in all the countries in which it has been adopted.” This is a perfect inductive conclusion.

In presenting this induction in an argument, the conclusion should be stated first. Then each of the countries in which the income tax has been adopted should be discussed and evidence introduced to show that it has proved practicable in every case. Finally, evidence should be brought forth to show that the countries named are the only ones in which the tax has been adopted. The conclusion should be stated in the form of a summary, which leaves the argument complete. It is a perfect inductive argument. While the reasoning process cannot be assailed, the facts upon which the induction is based may be disproved. Those advancing the argument must therefore be sure that the facts alleged are supported by sufficient evidence, while those seeking to overthrow the argument should be diligent in their search for evidence showing the weakness or impracticability of the tax in one or all of the countries cited.

From the above illustration it is plain that the validity of the reasoning of a perfect induction is easily determined. The mind at once determines whether or not the specific instances presented warrant the conclusion reached. The question of the validity of a perfect inductive argument is largely a question of fact. With the imperfect induction, however, the situation is somewhat different, for we have seen that the conclusion extends beyond the actual facts upon which it is based. From an examination of several observed specific instances a conclusion is drawn which covers instances unobserved. By it we pass from the known to the unknown. This process is sometimes called the inductive hazard. The application of this form of reasoning to argument is illustrated by the imperfect induction which is made by Lincoln in his Cooper Institute Address. Here he draws a conclusion as to what all the framers of the original Constitution thought about the slavery problem, by producing evidence to show what a part of them thought about it. After introducing specific evidence to show what each of twenty-three of these men thought, he says:

“Here then we have twenty-three of our thirty-nine fathers ‘who framed the government under which we live’, who have, upon their official responsibility and their corporeal oaths, acted upon the very question which the text affirms ‘they understood just as well, and even better, than we do now’; and twenty-one of them—a clear majority of the whole thirty-nine—so acting upon it as to make them guilty of gross political impropriety and willful perjury, if, in their understanding, any proper division between local and Federal authority, or anything in the Constitution they had made themselves, and sworn to support, forbade the Federal Government to control as to slavery in the Federal Territories. Thus the twenty-one acted; and as actions speak louder than words, so actions under such responsibility speak still louder....

“The remaining sixteen of the ‘thirty-nine’, so far as I have discovered, have left no trace of their understanding upon the direct question of Federal control in the Federal Territories. But there is much reason to believe that their understanding upon that question would not have appeared different from that of their twenty-three compeers, had it been manifested at all....

“The sum of the whole is that of our thirty-nine fathers who framed the original Constitution, twenty-one—a clear majority of the whole—certainly understood that no proper division of local from Federal authority, nor any part of the Constitution, forbade the Federal Government to control as to slavery in the Federal Territories; while all the rest had probably the same understanding. Such, unquestionably, was the understanding of our fathers who framed the original Constitution; and the text affirms that they understood the question ‘better than we.’”

The true test of an imperfect induction is not its sufficiency for the person who uses it, but its sufficiency for those to whom it is addressed. The argument is designed to produce a definite effect and in order to do this it must fulfil certain conditions. Even when these conditions are fulfilled the effect of the argument is problematical. Nevertheless, in order to approach its maximum efficiency an inductive argument must meet the requirements explained in the following section.

IV. Requirements for an effective inductive argument.

1. Perfect inductions.

In a perfect induction in which we have seen that the conclusion includes only the specific instances that have actually been examined, the only requirement is that the facts upon which it is based be true. The student must observe the rules regarding the sufficiency of evidence. He must be sure that he has introduced evidence which shows conclusively that each specific instance cited in support of the conclusion is true as a matter of fact. If he allows conjecture to enter into any one of them he cannot claim for his argument the solidity which characterizes the perfect induction. If in arguing for the necessity of additional sources of revenue for the United States government, he has stated the perfect inductive conclusion that “The expenditures of the United States government for the last three years have greatly exceeded its receipts,” he must substantiate his induction by exact reference to the reports of the Treasurer of the United States for the last three years. An investigation of these references must reveal the fact that each of these years has shown a large deficit. The greatest temptation against which the student will have to guard is that of careless generalization. He may know that a conclusion includes four specific instances. He may be certain that three of them support the conclusion, but he is not quite sure about the fourth. Nevertheless he conjectures regarding its validity and heedlessly proceeds to his conclusion. This is a bad habit to cultivate, because it results in loose, inaccurate thinking. A perfect induction should never be stated in an argument until each specific instance upon which it is based, and which it includes, has been determined to be an unquestioned fact.

2. Imperfect inductions.

The requirements for an imperfect induction are somewhat involved and demand the exercise of sound judgment in their application. An imperfect induction can never be relied upon with the same confidence that may be reposed in a perfect induction. This truth is apparent from the nature of the imperfect induction. In order to measure up to a high standard of effectiveness an imperfect induction must comply with the following requirements.

A. The number of specific instances supporting the conclusion must be sufficiently large to offset the probability of coincidence.

The problem of determining the number of specific instances which will justify us in relying upon an imperfect induction is most difficult. As we shall presently see, this number varies greatly with different classes of persons, events, and things about which we wish to reach conclusions. But before we consider this difficulty we must be sure that we have enough instances at hand to eliminate the element of chance. At least from the argumentative standpoint this is the most practical method of procedure. Suppose the student in his preparation for an argument finds that during the last year there has been a decrease in the value of manufactured articles produced in the state of Texas, that a similar decrease is shown in the state of New York, and that statistics relating to the state of Delaware show the same result. These facts could not be used to support the conclusion that the value of manufactured products of all the states of the Union has decreased during the last year, because it may be only a coincidence that their value has decreased in the states named. In all the other states of the Union there may have been an increase. The conclusion stated should belong to a perfect induction and could only stand upon proof of the fact that the value of the products manufactured in each and every one of the states showed a decrease. Moreover, it would not be safe to state the conclusion that the value of manufactured products in general shows a falling off in value during the past year and to cite the three instances named in support of that contention. In fact, the probability of coincidence is too great to enable us to arrive at any inductive conclusion other than that the manufactured products of Texas, New York, and Delaware for the past year show a decrease in value.

The student must be constantly on guard against this loose method of inductive reasoning. It is most prolific in indefinite and loosely stated conclusions seeking to masquerade under an appearance of validity. He should always examine his own conclusions as well as those of his opponent for the purpose of finding out whether the instances used to support them are merely the result of chance or coincidence. Let us suppose that the decrease observed in the three states named above has suggested the probability of the truth of one of the conclusions. The investigator should at once pick out a few of the most prominent manufacturing states and find statistics showing manufacturing values in them. For example, he might consult Massachusetts, Pennsylvania, Ohio, Michigan, Illinois, and Wisconsin. If the same decrease is found to have existed in these states the truth of the inductive conclusion becomes much more probable and at the same time the probability of coincidence becomes correspondingly less. The student, however, should continue his investigations and examine the statistics regarding all the manufacturing states of the Union. He should then frame his conclusion in such a way that it will stand supported by the evidence of all the specific instances.

B. The class of persons, events, or things about which the induction is made must be reasonably homogeneous.

After we have seen three or four elephants we feel pretty safe in saying that all elephants have trunks. After we have seen three or four red schoolhouses we do not feel safe in saying that all schoolhouses are red. The first class of objects is homogeneous, the second is not. Therefore we may safely generalize regarding the appearance and characteristics of all elephants from the three or four specimens which have come beneath our notice. As a class they possess in a marked degree common traits of character and appearance. No one member of the species is radically different from any other member. With schoolhouses, however, the situation is quite different. All schoolhouses in a given community may be built alike and the first three or four seen by an individual might be painted red; but since the class of schoolhouses is not homogeneous, he cannot therefore correctly arrive at the imperfect inductive conclusion that all schoolhouses are red. This illustration should indicate to the student who would employ imperfect induction that it is necessary to be careful in drawing a broad conclusion covering a class of persons, events, or things whose members he does not know to be reasonably homogeneous with respect to the point about which he wishes to argue.

To advance a step further in the consideration of this requirement, we must remember that it applies only to the homogeneity of the particular characteristic of the class regarding which a conclusion is desired. For example, if it is desired to arrive at some conclusion regarding the color of all schoolhouses, the inductive process could not well be applied because the class is by no means homogeneous in regard to this particular characteristic. However, if it is desired to arrive at a conclusion regarding the use to which all schoolhouses are put the imperfect induction may safely be used because the class is reasonably homogeneous in this characteristic.

C. The specific instances cited in support of the conclusion must be fair examples.

In an imperfect inductive argument the instances upon which the conclusion is based must be fairly representative of the class of persons, events, or things which it includes. A debater in an interscholastic contest took three examples of cities having the commission plan of city government as a basis for his argument in support of the proposition that all American cities should adopt the commission form of city government. He began by showing that the three cities,—Galveston, Des Moines, and Grand Rapids, were fair examples of American cities. He showed that they did not represent the exceedingly large cities nor the exceedingly small cities but that they possessed the chief characteristics of both. He produced evidence to prove that they were directly representative of nine-tenths of the cities in America and that the principles of government which would work well in these three cities, taken as examples, would work equally well in any American city. He then showed that the commission plan of city government had worked well in the three examples which he had proved to be fairly representative of all American cities.

The greatest temptation to error is that of selecting examples or incidents which are most favorable to the debater’s contentions. Such action is a flagrant violation of the great principle which should govern all argumentative discourse—the principle that truth should stand supreme over all contentions. It is not only dishonest to select unfair examples, but it is disloyal to those who uphold the debater in his efforts to persuade. Never should an example be presented which possesses characteristics unusual to the class which it purports to represent. An earnest effort should always be made to obtain the fairest examples possible.

D. Careful investigation must disclose no exceptions.

A person should seldom rely upon his own uncontradicted experience to support an inductive conclusion. The small child concludes that all children have fathers and mothers because it has a father and mother. The tropical savage concludes that all parts of the earth are warm because the part in which he lives is warm. Similarly we find reasonable persons adopting like generalizations based upon their own uncontradicted experience. The business man denounces all public officials as dishonest because he has found that two or three are dishonest. The farmer denounces all lawyers as dishonest because one lawyer has treated him dishonestly. In each of these cases it is evident that a little careful investigation would disclose enough exceptions to overthrow the conclusion.

The debater should examine his own inductions as well as those of his opponent for the purpose of discovering possible exceptions. The man who declared that all trades-union men are anarchists would have found the exceptions to his rule so overwhelming as to make his conclusion appear ridiculous. The difficulty is that the abnormal and exceptional instances which we know loom so large in our minds that they become prejudices and crowd out calm reason. The few union men who have destroyed life and property should not be made the specific instances supporting an induction regarding the whole class of trades-union men. The few college men who drink, swear, and carouse should not be made the specific instances supporting an induction regarding the whole class of college men. Every induction should be examined carefully for the purpose of discovering exceptions.

After all the foregoing requirements have been met there still remains one essential. The conclusion must be reasonable. This is the ultimate test of validity. We have become so familiar with the usual course of nature that we instinctively question that which appears to run contrary thereto. Nothing occurs without an adequate cause. Upon this principle we base our judgment regarding all matters which transcend our own experience. Most of us have passed the superstitious days when the breaking of a looking glass was regarded as a sure sign that someone in the family would die before the end of the year. Even the time-honored Friday and number thirteen with their attendant superstitious disasters no longer have a large following. Scientific investigation and the present age of commercialism have crowded out superstition and put common sense in its place. The average mind is highly reasonable and requires some causal connection between the breaking of a looking glass and the death of a person. It would refuse to believe that one caused the other, or that one was the sign of the other, even though there might be a hundred instances to warrant the induction and not one to contradict it. The final requirement for an imperfect inductive argument is that it be reasonable.

1. The number of specific instances supporting the conclusion must be sufficiently large to offset the probability of coincidence.

2. The class of persons, events, or things about which the induction is made must be reasonably homogeneous.

3. The specific instances cited in support of the conclusion must be fair examples.

4. Careful investigation must disclose no exceptions.

5. The conclusion must be reasonable.

1. Are the following inductions perfect or imperfect?

(1) All men are mortal.

(2) All Irving’s books are interesting (or uninteresting).

(3) All the presidents of the United States who have been assassinated were Republicans.

(4) “Pythagoras was misunderstood, and Socrates, and Jesus, and Luther, and Copernicus, and Galileo, and Newton, and every pure and wise spirit that ever took flesh. To be great is to be misunderstood.”

(5) Money is the root of all evil.

2. Give in full the specific instances upon which each of the foregoing inductions is based.

3. Apply the requirements for validity to each of the inductions in exercise one, and state the result.

4. Write an inductive argument of four hundred words.

Deductive argument consists of the application of deductive processes of reasoning to argumentative discourse. This process of applying logical principles is somewhat more complicated than that involved in induction. In some respects it is more important that the student thoroughly master deduction than it is that he master induction. Fallacies are more easily concealed in the deductive process than in the inductive process. Nevertheless, when the fallacy is once detected it can be set forth clearly by anyone who understands this form of reasoning. Neither the inductive nor the deductive form of reasoning is often found alone. Most arguments contain both of these processes and in some cases they are very closely interwoven. This fact necessitates a thorough study of both processes. From this standpoint a knowledge of one form is as important as a knowledge of the other. In order that we may thoroughly understand the application of the deductive process to argument we must first consider separately that process of reasoning.

I. Deductive reasoning.

By deductive reasoning we arrive at a conclusion regarding a particular person, event, or thing by reason of our knowledge regarding the whole class to which the particular person, event, or thing belongs. In this sense it is the opposite of induction. We conclude that a particular book is interesting because we know that all the books written by the author of this book are interesting. We may say that deductive reasoning begins where inductive reasoning leaves off. For example, we found that we could arrive at the imperfect inductive conclusion that all of Stevenson’s books are interesting because each one of a number of his books which we had read was interesting. Since (1) the number of specific instances cited were sufficient to offset the probability of coincidence, (2) the class was fairly homogeneous, (3) the examples were fair, (4) we found upon investigation that there were no exceptions, and (5) from the character of the author and other circumstances the conclusion seemed reasonable, we concluded that our induction was sound. Now, taking this conclusion as true we may apply it to any one of Stevenson’s works not yet examined and thus determine that that work is interesting. It must be kept in mind, however, that a deduction based upon an imperfect induction is no stronger than that imperfect induction. The imperfect induction gains no strength by reason of its having a valid deduction based upon it. Nevertheless, unsound arguments are often given a superficial appearance of validity by this means.

We may more clearly indicate the relation of the inductive and the deductive process by arranging the material of the foregoing illustration in the following manner.

A. Inductive process.

1. Specific instances.

(1) Treasure Island, written by Stevenson is interesting.

(2) Kidnapped, written by Stevenson is interesting.

(3) David Balfour, written by Stevenson is interesting.

(4) Prince Otto, written by Stevenson is interesting.

(5) St. Ives, written by Stevenson is interesting.

2. Conclusion: All books written by Stevenson are interesting.

B. Deductive process.

1. Major Premise: All books written by Stevenson are interesting.

2. Minor Premise: The Silverado Squatters was written by Stevenson.

3. Conclusion: Therefore The Silverado Squatters is interesting.

It will be observed that the inductive conclusion forms the first statement, the basis, or what is called in logic, the major premise of the deductive process. By induction we build several specific instances into a conclusion, and from that conclusion we reason down again to one particular instance. This illustration should serve to make plain to the student the relation between induction and deduction and the reason why the two processes are so often combined in an argument.

In logic the deductive form presented above is called a syllogism. It consists of three statements called Major Premise, Minor Premise, and Conclusion. This syllogism occurs in different forms, but we are concerned with only the typical form above presented, because it is to this form that we intend to reduce our own arguments and the arguments of our opponents in order that we may test their validity.

Each statement in a syllogism is composed of two parts, called terms. The names of these terms as well as their proper location in the syllogism are indicated by the following form:

The student will observe that each statement in the syllogism is composed of two terms and that each term appears twice in the entire syllogism, but only once in any one statement. The major term represents the largest element in the syllogism namely,—the class of persons who should study argumentation. The minor term represents the smallest element in the syllogism namely,—Paul Morton, the particular person about whom a conclusion is reached. The middle term serves as an intermediary or connecting link which binds the minor term to the major term. It does not appear in the conclusion but is cast away after it has served its purpose in assigning the minor term,—Paul Morton, to the major term,—those who should study argumentation.

In the typical form of the syllogism with which we are concerned the major premise should always be in the universal affirmative-form. By universal affirmative is meant that the assertion is made with regard to the class as a whole as: “All men are mortal,” “All laws should be obeyed,” “All students should pay their bills,” etc. No part of the class of persons, events, or things about which an assertion is made should be left outside the statement as would be the case if the statements read—“Some laws should be obeyed,” “Some students should pay their bills.”

From the foregoing discussion it is evident that the deductive syllogism, in order to be valid, must be constructed in accordance with certain well defined rules. In books of logic the student will find these rules discussed at some length and their application set forth in detail. For our purpose it is only necessary to refer to them and keep them clearly in mind in connection with the discussion here given. The rules of the syllogism with which we are concerned are as follows:

1. A syllogism must contain three terms, Major term, Minor term, and Middle term.

2. A syllogism must consist of three complete statements, Major Premise, Minor Premise, and Conclusion.

3. The middle term must be distributed at least once in the premises. A term is distributed when it is universal in its application or taken in its whole length of meaning.

4. A term cannot be distributed in the conclusion unless it is distributed in the premises.

5. No conclusion can be drawn from two negative premises.

6. A negative conclusion always follows one negative premise and a negative conclusion cannot be obtained unless one of the premises is negative.

For the purpose of making more plain the relation between the terms and the statements in a syllogism let us consider the old method of graphical representation by means of circles.

I. All college men should study argumentation.

II. Paul Morton is a college man.

III. Paul Morton should study argumentation.

From the diagrams on the following page it is seen that in the major premise the middle term must be wholly included within the major term. The entire class of college men must be included within the class of those who should study argumentation. Not one single college man must be left outside the class. In the minor premise the minor term must be clearly and unmistakably included within the middle term. Paul Morton must be a college man. He must not be a banker or a janitor. In the conclusion the minor term must be included within the major term. This position inevitably results from the two preceding situations. If the middle term, college men, is wholly included within the major term, those who should study argumentation, and if the minor term, Paul Morton, is wholly included within the middle term, college men, then it cannot be otherwise than that the minor term is included within the major term. In other words, Paul Morton is definitely assigned to the class of those who should study argumentation.

We may represent the whole syllogism in the following manner:

The student should be sure that he has mastered each step in the construction of a valid syllogism of the typical form before he passes on to the following section of this chapter.

II. The application of deductive reasoning to deductive argument.

From our examination of the deductive process of reasoning we cannot but realize its importance when applied to the construction of an argument. One cannot advance far into any argumentative discourse without encountering deduction in some form. A student in a class debate defended the following proposition with the inductive arguments given below: “Resolved that tariff should be imposed for revenue only.” In his introduction the student declared that the protective tariff should be removed. In support of his contention he offered five substantial reasons which he claimed included the vital points at issue. These reasons were as follows:

A. High duties encourage the formation of trusts.

B. The high cost of living results from protection.

C. Protection is unjust to the American people.

D. Protection breeds corruption.

E. The usefulness of the protective tariff has long ceased.

Each of the above reasons for the removal of the protective tariff is a deductive argument. The complete deductive process is seen when we state each argument in syllogistic form.

1. All things which encourage the formation of trusts should be abolished.

2. The protective tariff encourages the formation of trusts.

3. Therefore the protective tariff should be abolished.

1. All things which are the cause of the high cost of living should be abolished.

2. The protective tariff is a cause of the high cost of living.

3. Therefore the protective tariff should be abolished.

1. All things which are unjust to the American people should be abolished.

2. The protective tariff is unjust to the American people.

3. Therefore the protective tariff should be abolished.

1. All things which breed corruption should be abolished.

2. The protective tariff breeds corruption.

3. Therefore the protective tariff should be abolished.

1. All governmental policies the usefulness of which has long since ceased should be abolished.

2. The protective tariff is a governmental policy the usefulness of which has long since ceased.

3. Therefore the protective tariff should be abolished.

Each of the above syllogisms stands as an argument for the abolition of the protective tariff; or, to take the standpoint of the proposition each supports the contention that the tariff should be imposed for revenue only. All of the five reasons lead to a single conclusion. We may represent this relation by the following diagram:

This use of deductions is very simple, but in dealing with a combination of induction and deduction the process may become very complicated. For example, the major premise of the first syllogism above stated has back of it another logical process of reasoning. Why should all things which encourage the formation of trusts be abolished? What proof can we show to establish the conclusion (in A, the major premise) that the formation of trusts should be discouraged rather than encouraged? It must be established in a logical manner. We may establish it by induction by showing that each one of a large number of trusts has had injurious effects. After we have introduced positive evidence establishing a perfect or an imperfect induction we have laid a sufficiently strong foundation for the deductive syllogism.

On the other hand, we may establish the major premise of the above syllogism by means of deduction. To do this we might find evidence which would prove that trusts increase the cost of producing commodities and decrease their quality. In this case it would be necessary to introduce evidence only along the line which would show that this evil was characteristic of all trusts. This would be an induction, because the general principle used as a major premise would be based upon specific instances. Beginning with this induction we would build up the following syllogism, the conclusion of which supports the major premise of the foregoing syllogism.

1. All forms of business organization which increase the cost of producing commodities and decrease their quality are an industrial evil.

2. The trust is a form of business organization which increases the cost of production and decreases the quality of commodities.

3. Therefore the trust is an industrial evil.

Then to continue our deductive reasoning we would construct the following syllogism based upon the foregoing:

1. All industrial evils should be discouraged.

2. The formation of trusts is an industrial evil.

3. Therefore the formation of trusts should be discouraged.

The exact phraseology has not been kept throughout the above line of reasoning, because seldom in any practical work do we find the exact words repeated except for emphasis. However, it requires the exercise of only ordinary ingenuity to follow precisely the entire reasoning processes involved in the foregoing argument.

An excellent example of the use of the deductive syllogism for the purpose of showing that an opponent’s deductive argument is unsound is the following extract from Lincoln’s reply to Douglas in the Fifth Joint Debate at Galesburg:

“In the second clause of the sixth article, I believe it is, of the Constitution of the United States we find the following language, ‘This Constitution and the laws of the United States which shall be made in pursuance thereof, and all the treaties made, or which shall be made under the authority of the United States, shall be the supreme law of the land; and the judges in every state shall be bound thereby, anything in the Constitution or laws of any state to the contrary notwithstanding.

“The essence of the Dred Scott case is compressed into the sentence which I will now read, ‘Now as we have already said in an earlier part of this opinion, upon a different point, the right of property in a slave is distinctly and expressly affirmed in the Constitution.’ I repeat it, ‘The right of property in a slave is distinctly expressed and affirmed in the Constitution.’ What is it to be ‘affirmed in the Constitution? Made firm in the Constitution,—so made that it cannot be separated from the Constitution without breaking the Constitution; durable as the Constitution, and part of the Constitution. Now remembering the provision of the Constitution which I have read; affirming that that instrument is the supreme law of the land; that the Judges of every state shall be bound by it, any law or constitution of any state to the contrary, notwithstanding; that the right of property in a slave is affirmed in that Constitution, is made, formed into, and cannot be separated from it without breaking it; durable as the instrument; part of the instrument; what follows as a short and even syllogistic argument from it? I think it follows, and I submit to the consideration of men capable of arguing whether as I state it, in syllogistic form, the argument has any faults in it? (1) Nothing in the constitution or laws of any state can destroy a right distinctly and expressly affirmed in the Constitution of the United States. (2) The right of property in a slave is distinctly and expressly affirmed in the Constitution of the United States. (3) Therefore nothing in the Constitution or laws of any state can destroy the right of property in a slave.

“I believe that no fault can be pointed out in that argument; assuming the truth of the premises, the conclusion, so far as I have capacity at all to understand it, follows inevitably. There is a fault in it as I think, but the fault is not in the reasoning; but the fault in fact is a fault of the premises. I believe that the right of property in a slave is not expressly and distinctly affirmed in the Constitution, and Judge Douglas thinks it is. I believe that the Supreme Court and the advocates of that decision may search in vain for the place in the Constitution where the right of property in a slave is distinctly and expressly affirmed. I say, therefore, that I think one of the premises is not true in fact.”

To give examples of all the forms in which deduction may be applied to argument is impossible. The foregoing examples are merely suggestive. They serve to make plain the practical use which can be made of this logical process. The student must master the underlying principles herein suggested and apply them to his own work.

III. The enthymeme.

An enthymeme is an incomplete syllogism. It is a syllogism in which only one or two of the statements are expressed. An example of an enthymeme is the following proposition, “The protective tariff should be abolished because it encourages the formation of trusts.” This is the form in which we most commonly encounter deductive reasoning. Seldom is the complete syllogism expressed. It therefore becomes our task to construct from this enthymeme a complete syllogism. Our first duty, then, is to find out what parts of the syllogism are contained in the enthymeme and then strive to supply the missing parts. Usually the major premise is omitted. This requires that it be supplied from a consideration of the minor premise and the conclusion. In almost all cases the conclusion is expressed. If it is not expressed it is clearly implied. This supplies the minor term (the thing about which something is said) and the major term (the thing that is said about it). From these two terms it is usually easy to find a middle term which will serve as a connecting link. The process of building syllogisms upon enthymemes is comparatively simple if the student will always find the conclusion and then divide it into the two terms of which it is composed.

In order to illustrate the application of the principles above expressed, let us reduce an enthymeme to the syllogistic form. We shall take for our example the enthymeme, “The railroads of the United States should be under Federal control because they are a natural monopoly.” The parts of a syllogism which are expressed in this statement must be found and of these the conclusion should be first determined. In this case the conclusion is “The railroads of the United States should be under Federal control.” “Railroads of the United States,” is the minor term, and “should be under Federal control” is the major term. Now, to represent what we have thus far discovered we apply the order of statements and terms which were employed in the discussion of Deductive Reasoning. The result is as follows:

We thus have the entire syllogism completed with the exception of the middle term. Our next task is to find this middle term. It must include the minor term and it must be included in the major term. A reference to the diagrams given in connection with the discussion of Deductive Reasoning will make this plain. With this requirement in mind we consider the enthymeme and find that the reason assigned for placing railroads under Federal control is that they are a natural monopoly. This gives us the middle term as it appears in the minor premise. We then take this middle term and cast it into the universal affirmative form, “All natural monopolies.” We now have the enthymeme with which we started out, reduced to the following syllogistic form:

Major Premise: All natural monopolies should be under Federal control.

Minor Premise: The railroads of the United States are a natural monopoly.

Conclusion: Therefore the railroads of the United States should be under Federal control.

This places clearly before us the deductive argument contained in the enthymeme. The syllogism is complete. The statements and terms are in their proper order and form, and the conclusion follows logically and inevitably from the premises. The form of the syllogism as it stands is therefore sound. If the two premises are true as a matter of fact, the conclusion must be true. Having determined these matters we now scrutinize each of the premises to see whether there is sufficient evidence to establish its truth. In the first place is it true that all natural monopolies should be under Federal control? What is a natural monopoly and why should it be under Federal control? All the sources of evidence must be searched for facts and statements of authority to substantiate this assertion. On this point opinions differ and the student must strive to find out the truth for himself. The other question which he must answer is, “Are the railroads of the United States a natural monopoly?” Here again the student must resort to the sources of evidence and by their aid answer the question in the affirmative or in the negative. If he can introduce enough evidence to prove that all natural monopolies in the United States should be under Federal control, and that the railroads are a natural monopoly, then he has completed a sound deductive argument in favor of the Federal control of railroads. This example ought to make clear the method of reducing an enthymeme to the syllogistic form and the use to which this form may then be put.

Before leaving this subject a word of caution is necessary. Do not be confused by the form in which the enthymeme appears. Be sure that you have the real conclusion before you begin the construction of the rest of the syllogism. If you have failed to grasp what the enthymeme really says you are liable to get a wrong conclusion, and if you get a wrong conclusion the whole syllogism will be wrong. High sounding oratorical phrases and sentences are often confusing. Plainness is sometimes avoided by the speaker for the express purpose of concealing a fault in his argument. Even truth expressed in an unusual form is often misleading when we seek to reduce it to logical terms.

Some difficulty is usually experienced in reducing the beatitudes to the typical syllogistic form. For example, in reducing the enthymeme “Blessed are the pure in heart, for they shall see God,” the inexperienced student usually says that the conclusion is, “The blessed shall see God.” A syllogism built upon this conclusion would appear as follows:

1. All those who are pure in heart shall see God.

2. The blessed are pure in heart.

3. Therefore the blessed shall see God.

This is a valid syllogism so far as the form is concerned; but it is of no use in throwing light upon the truth or falsity of the enthymeme, because the conclusion with which we started was not the true conclusion. This fault is fatal to the success of the argument, because after the syllogism is completed the student usually devotes his entire attention to proving the truth or falsity of the two premises and seldom gives any further attention to the conclusion.

Another erroneous statement of the conclusion expressed in the above enthymeme is often given. It is “All those who are blessed shall see God.” With this conclusion as a starting point we may construct the following syllogism:

1. All those who are blessed shall see God.

2. The pure in heart are blessed.

3. Therefore the pure in heart shall see God.

Again we have an invalid syllogism, because the conclusion from which we built it is not the true conclusion expressed in the enthymeme. Likewise there are many pitfalls for him who seeks to find the true meaning of any statement worded in a manner different from that in which we are accustomed to speak. The very difficulty, however, suggests the remedy. The student should always reduce the complicated statement to plain, ordinary, everyday English before attempting to find the conclusion. Reducing the enthymeme under consideration in this manner we have this simple statement, “The pure in heart are blessed because they shall see God.” When we have put the statement in this form the real conclusion is readily seen. It is “The pure in heart are blessed.” The remainder of the enthymeme is a statement of the reason why the pure in heart are blessed. With this as a basis we easily construct a valid syllogism.

1. All those who shall see God are blessed.

2. The pure in heart shall see God.

3. Therefore the pure in heart are blessed.

In closing this discussion it may be remarked that actual practice in the use of the deductive process as well as its application to argument is the only way in which real practical benefit may be derived from the knowledge here gained. This knowledge should not be reserved for use in the class room but should be used all the time and everywhere.