The Informal Fallacies: Necessary in Training in Debate and Correct Reasoning

ONE’S TRAINING in debate and correct reasoning is incomplete without the study of the various forms of what we call informal fallacies. You will notice that many tend to commit these various forms or faulty reasoning without realizing that they are in fact making erroneous arguments.

Errors in reasoning, these logical fallacies occur frequently enough, either alone or in combination, to deserve special attention. Fallacy is false reasoning, a bad method of argument, whether deductive or inductive.

Actually, there are numerous forms of bad arguments as arguing badly may be done in an infinity of ways. But the term fallacy usually pertains to typical flaws in arguments that many nonetheless consider persuasive though erroneous. The informal fallacies are called so because they display a persuasiveness that leans on informal aspects like ambiguity, fear, prejudice, and so forth. If we want to be ready with a good defense against deception, it is imperative that we study these fallacies.

Fallacies of Relevance

The fallacies of relevance are unsuccessful in providing satisfactory justification to establish belief in the truth of their conclusions. Logicians of the Medieval and Renaissance had identified these fallacies; the Latin names they gave to them have passed into ordinary use.

1. Irrelevant Conclusion (Ignoratio elenchi)

The fallacy named ignoratio elenchi attempts to found the truth of a conclusion by offering proofs or evidences that actually render support for a completely different conclusion. When you prove a conclusion other than the one that should be proved, you commit this fallacy which is also called “fallacy of irrelevant conclusion,” “ignoring the issue,” “missing the point,” “red herring,” and “ignorance of the question.”

The Latin word elenchi came from the Greek word elencho, which means “refutation.” One way to refute a claim is to establish the truth of its contradictory—because contradictory statements cannot be both true at the same time.  Now, one is considered “ignorant of the refutation” or “missing the issue” if in an attempt to refute a certain proposition, he proves or establishes statements other than the contradictory of the statement to be falsified. Consider this argument:

Evil exists.

Therefore, an all-loving and all-powerful God does not exist.

Suppose that proponents of atheism have proved that evil exists. But our question is, is the fact that evil exists necessarily inconsistent with God’s existence? Is the statement “Evil exists” the contradictory of “God exists”? Or, can it be that evil exists and still God exists? Is it logically inconsistent, for instance, to think that God allows evil? What if God uses evil to maximize the amount of good in the universe? Or, what if the existence of evil would help to establish that God is ultimately just? In these logically possible scenarios, God and evil can coexist.

Therefore, the statement “Evil exists” may be used to conclude that this world is not perfect, or that not all humans are good, or that some events are destructive; but it does not necessarily prove that God does not exist. Therefore, the above-mentioned argument is invalid for it commits the fallacy ignoratio elenchi.

The ignoratio elenchi is very common that some consider all the fallacies under ‘fallacies of relevance’ as mere various forms of ignoratio elenchi. Many logicians nonetheless maintain that it is distinct from anything else under ‘fallacies of relevance.’

2. Appeal to Force (Argumentum ad baculum)

The appeal to force is someone’s use of power over another who dares disagree to accept his proposition. You commit this fallacy when you pursue to establish a conclusion by resorting to coercion, intimidation, threat, or strong-arm tactics. It proposes the idea that ‘might is right’ and is also called ‘appeal to the stick’. This type of fallacy is inclined to suggest something like:

I believe that Obama is the greatest American president of all times.

If you don’t accept what I believe, I will fail you.

Therefore, Obama is the greatest American president of all times.

Notice that the conclusion could still be false even if we accept that all of the premises were true. Certainly, failing you is not the logical and neither a good way to demonstrate that the conclusion is acceptable.

3. Appeal to Pity (Argumentum ad misericordiam)

You commit this fallacy when you attempt to gain acceptance by drawing attention to the misfortune that would befall you or others should we not accept your conclusion. This is logically flawed for it avoids the point at hand by appealing to mercy, sympathy, or compassion. Example:

I’m pregnant and I can’t go to school for another semester if I don’t graduate this year. My father doesn’t know about my condition yet and would kill me if he learns that I also failed in your subject. So I deserve to pass your subject.

The speaker has not proven that she deserves to pass the subject. She has proven rather that she would be miserable if she fails it. This is more of emotional blackmailingthan reasoning.

4. Appeal to Emotion

It capitalizes on emotional language to stimulate intense feelings, attempting to lead someone into acceptance of a conclusion:

Pre-marital sex is not only practically evil and immoral but is also against the ideals of cultural decency. Moreover, to engage in it is to transgress the rightful and just principle of Christianity because it causes intense destruction to the indispensable sanctity of marriage, as all virtuous and discerning citizens of this nation understand. Therefore, pre-marital sex has not entered the Filipino culture.

True, the sentimental tone of the premises might excite strong emotions. Nevertheless, the produced feelings by this argument have nothing to do with the truth of its conclusion.

5. Appeal to the people (Argumentum ad populum)

When you claim that an idea should be accepted by pointing to a large number of people favoring it or by appealing to popularity or opinions, passions or prejudices of the people or traditional institutions, you commit this fallacy. This is also called the bandwagon appeal or joining the bandwagon. Example:

The Philippines is one of the very few nations left that has not legalized divorce yet.

Therefore, we must legalize divorce in the Philippines.

Granting for the sake of argumentation that the premise is true, still it doesn’t necessitate us to accept the conclusion as also true, for the measure of what is right is not whether or not the majority advocates it.   

6. Appeal to False Authority (Argumentum ad verecundiam)

Here, the view or opinion of a notable person, himself expert in some other fieldof specialization is presumed to warrant the truth of a conclusion. In other words, a wrong or unqualified authority is here referred to to prove a conclusion.

Example:

Next year is the second coming of Jesus Christ. Manny Pacquiao believes so.

Though Manny Pacquiao could be recognized as an authority in boxing, his opinion regarding Judgment Day nevertheless does not make the alleged second advent of Jesus Christ next year to be true.

7. Appeal to Authority (argumentum ad auctoritatem)

You commit this fallacy if you assert a proposition as true on the sole basis that an expert holds it. Authorities too are not free from errors and have biases in a certain issue. Take this example:

There is no God. My professor who has doctoral degree in Philosophy and Theology says so.

The truth of a statement is not grounded on the conviction of an individual no matter how accomplished or talented he is. Even the most expert of authorities could be incorrect in fields where they are knowledgeable or skilled. Their statement may be acknowledged as inductive or supporting evidence, never as deductive or necessary proof.

8. Argument against the person (Argumentum ad hominem)

Ad hominem is a Latin term meaning “to the man”. This fallacy happens when the “person” or personality of the arguer is attacked, rather than his argument. You are guilty of this fallacy when you discard a proposition just because the person who stated it has discreditable character. Example:

Why should we believe in what this man says that divorce destroys the sacredness of marriage?  Isn’t he an illegitimate son?

Logically, not only is it possible for a disreputable individual to propose something that is correct, also, his opinions and arguments should be evaluated independent of his character or traits.

9. Appeal to Ignorance (Argumentum ad ignoratiam)

Here, a proposition’s truth or falsity is accepted unless it is proven otherwise. When you assert that a thing is true because it cannot be proven false, or a thing is false because it cannot be proven true, you commit the fallacy called argumentum ad ignoratiam. Example:

No one has categorically proven that there are no ghosts.

Therefore, there are ghosts.

Remember that a proposition is not proven to be true just because there is no evidence against it, nor is it false, just because there is no available proof or evidence provided for it.

Fallacies of Presumption

The fallacies of presumption are ineffective in providing sufficing reason for their conclusion to be accepted as true. The erroneous reasoning in these fallacies is basically the result of an inferred supposition of some further proposition, the truth of which is either doubtful or still debatable.

1. Accident

The fallacy of accident states some principles that are generally true and errs when it applies this principle to an accidental or exceptional case. In other words, this fallacy is committed when you take a general rule and apply it to its atypical or exceptional cases. Example:

Col. Zaragoza is a criminal. He killed enemies during the war and as we all know, he who kills another commits a crime.

Though it is a general rule that killing is a crime, for a soldier to do so during wars is sanctioned by the law and is therefore an exception to this general rule.

2. Converse accident

It is also called “hasty generalization.” It is concluding based on insufficient or unrepresentative evidence.

KobeBryant has tattoo and is an excellent basketball player.

Therefore, people who have tattoo are excellent basketball players.

Notice that a single or few instances are not enough to found the truth of such a general statement. The argument is invalid since it is easy for the conclusion to be false even though the premise is true.

3. False Cause (Post hoc ergo propter hoc)

There was an eclipse on Monday evening.

On Tuesday morning I got migraine.

Therefore, the eclipse caused my migraine.

When you assume that just because one event follows another then the first is the cause of the second, you commit the fallacy of false cause. The argument above commits the fallacy which is also known as post hoc, ergo propter hoc, meaning “after this, therefore because of this. “

4. Begging the Question (Petitio principii)

This fallacy takes two forms:

4.1. Assumptio non probata

This is committed when what has yet to be proven true is assumed as already proved and is used as a premise for what one wants to conclude.

Example:

All Kapampangan are boastful. (to be proven true yet)

Therefore, Don, a Kapampangan, is boastful.

4.2. Circular reasoning (Circulus in probando)

This occurs when you use a premise to prove the conclusion and then use the same conclusion to prove the premise.

Jay-jay is the 1st honor of the class because he is the most intelligent of all. Why is he the most intelligent? Because he is the 1st honor of the class.

5. Complex question

This fallacy assumes the truth of its own conclusion by loading it implicitly in the question that is asked. Example:

Have you stopped taking prohibited drugs?

If so, then you admit that you do take prohibited drugs.

If not, then you must still be taking prohibited drugs.

Therefore, you are taking prohibited drugs.

6. Neglected aspect

This happens when you conclude based on some pieces of evidence while “neglecting” or ignoring those that would endorse other conclusion. Example:

Brand A car costs less to purchase and operate.

(But it costs more to maintain and repair than other brands)

Brand A car therefore is the best brand.

Fallacies of Ambiguity

The error of these forms of invalid arguments originates from the imprecise use of language that results in ambiguity or confusion.  An ambiguous word, phrase, or sentence is that which has two or more distinct meanings. Hence, the fallacies of ambiguity include a confusion of two or more different senses.

1. Equivocation

This takes place when in an argument, one of the meanings of an ambiguous word or phrase is used in one statement and its other meaning in another proposition. Example:

Man is a rational being.

No woman is a man.

Therefore, no woman is a rational being.

The term “man” is used in two different senses here. The term “man” in the first premise is used as a generic term to include all human beings regardless of gender. In the second premise however, “man” is used in a specific sense as applying only to the male sex.

2. Amphiboly

An amphiboly occurs when it is the grammatical construction of a sentence that creates the ambiguity. Example:

A candidate for election: I oppose taxes which impede economic development.

Reporter: The candidate therefore opposes all kinds of taxes for they impede economic development.

If what the candidate is trying to say is that he opposes only those taxes that impede economic development, then his statement is indeed ambiguously constructed.

3. Accent

The fallacy of accent emerges when the ambiguity is created by a change in spoken or written emphasis. Example:

The tutor says John-john is stupid.

Therefore, John-john is stupid according to the tutor.

Depending on the emphasis or pausing to be applied in the sentence, the stupid one referred to could either be ‘John-john’ or ‘the tutor’.

4. Composition

Here, the quality possessed by members of a class (or parts of a greater whole) is confused to be also exhibited by the entire class (or whole). Example:

When a feather is dropped from a 6-story building, it glides to earth very slowly. Therefore, if I would drop this pillow composed of feathers from a 6-story building, it too will float to earth slowly.

What is true to a single feather may not be true to the group of feathers contained within the pillow.

Note that this is different from fallacy of converse accident, which inappropriately generalizes from an atypical particular case (as in “One of the feathers composing the pillow is black; therefore, the pillow is black.”). The lesson to be learned in the fallacy of composition is that even when something can really be said of each individual part, it does not necessarily follow that the same can truly be said of the entire class.

5. Division

Being the converse of the fallacy of composition, fallacy of division claims that what can be said of the whole can necessarily be said of its parts. Example:

The American judicial system is a fair system.

Therefore, Mr. X will get a fair trial.

The American judicial system is generally and comparatively fair. It has fairness as its attribute. Nevertheless, this does not mean that every trial within that system is automatically fair in itself.

Unlike the fallacy of accident, the key point in the fallacy of division is that even when something can truly be said of a whole class, it does not automatically follow that the same can be truly said of each of its single members.

Miscellaneous Fallacies

The following types of invalid arguments do not fall under the fallacies of relevance, presumption, and ambiguity, but are nonetheless considered informal fallacies.

1. Self-contradiction

It involves submitting an argument which carries contradictory or inconsistent premise(s). The following is an example of a self-contradicting statement:

The doctor cured the incurable disease.

The error in reasoning here lies in the principle that an inconsistent premise can never produce a necessarily true conclusion.

2. False analogy

In a false analogy, one erroneously presupposes that because two things are alike in one aspect, they must be alike in others.

In His will to gather the children of Jerusalem together, the Lord Jesus Christ, said, “I wanted to gather your children together, as a hen gathers her chicks under her wings…” (Mt. 23:37)

Preacher:Therefore, Jesus Christ, like a real hen, must have (physical) wings.

Through analogy, Christ compared His attempt to gather together the children of Jerusalem to the effort of a hen in gathering her chicks under her wings. In that sense, Jesus and a hen are alike. But to conclude that Jesus is a hen in his state of being, or has wings, is not only obviously erroneous but also is funny and weird.

Analogies can be effective in illustrating a point, but they are not proof.

3. Black or white

Also called false dichotomy, either or fallacy, bifurcation, and falsedilemma, the black or white fallacy arises when one limits the options to two, oftentimes between the extremes, when in fact there are more.

Either learn to speak English fluently or you won’t be able to get any job.

Although learning to speak English fluently is necessary, many occupations do not require it.

4. Fallacy of significance

This is also called statistical fallacy and is committed when one concludes based on the statistics or evidences presented without questioning how they are gathered or how “significant” they are to the issue. Example:

According to survey, more dentists use Brand X toothpaste.

Statements like this which are commonly used to persuade people to patronize a particular product can be deceiving. If by ‘more’, the survey means 12 versus 11, then the difference is not that significant. Notice too that the statement does not tell much about the survey.

5. Quoting out of context

This is another fallacy committed very commonly especially by advocacy writers.

It involves quoting very selectively and unfairly from a longer passage, thereby distorting the meaning of the original text:

Original: “I would enjoy this food if, and only if, it were the only food available, or if I were on a desert island and had nothing else to eat.”

Quotation: “I would enjoy this food . . . (even) if I were on a desert island . . . . “

6. Straw man fallacy

You are guilty of this fallacy if you construe someone’s position on a given matter in such a way as to make him most susceptible to attack and criticism. Commonly, it is done by reducing a complex argument to an exaggeratedly simple form, thereby leaving out some of its important components.

Professor: “You should be dedicated in your studies if you really want to succeed in your future profession.”

Joe: “Why, we just had our class today. Do we have to study every minute? Should we not eat and have fun just to have successful career in the future?”

Notice that Joe’s response is deceiving because the professor never said anything about studying every minute. Take note, too, that the advice does not necessarily suggest not eating and not having fun.

7. Non sequitor

Validity is the condition of an argument in which when the premises are true, the conclusion cannot be false (always true). In a valid argument, the truth of the premises necessitates the truth of the conclusion—that is, the conclusion necessarily follows from the premises.

Logically speaking, all invalid or fallacious arguments have one thing in common: their conclusions do not follow from their premises. It is therefore not wrong to call all kinds of fallacious argument non-sequitor, which means ‘it does not follow.’ (© 2014 by Jensen DG. Mañebog/MyInfoBasket.com)

ALSO CHECK OUT:
Reasoning and Debate: A Handbook and a Textbook by Jensen DG. Mañebog

Also Check Out: From Socrates to Mill: An Analysis of Prominent Ethical Theories, also by author Jensen DG. Mañebog

INTERACTIVE ONLINE ACTIVITY

Go online to www.OurHappySchool.com. Through its search engine (upper right section), look for the online debate “Same Sex Marriage: Good or Bad for our Society?” Read the article and the students’ comments. Choose four student’s comments with which you disagree. Leave a courteous but logical replies (click the button ‘reply’). If the owner of the comment replied back, diplomatically answer his/her new arguments. Print your conversation threads and submit the print out to your professor.

SUPPLEMENTARY ONLINE READING

Look for the article “Philippine Supreme Court Justices: Should they be elected or not?” through the search engine (upper right section) of www.OurHappySchool.com. Read the article and the comments. Pay attention to the Toulmin type of argument used and the informal fallacies committed by some netizens.