The slides aim to train members of Ateneo Debate Union to detect fallacies in argumentation. It is the hope that this would enhance their case construction skills. The principles used borrows heavily from logic.
When inferences are defective, they are called fallacious. When defective styles of reasoning are repeated over and over, because people often get fooled by them, then we have an argumentative fallacy that is worth flagging with a name. The number and variety of argumentative fallacies are limited only by the imagination. Consequently, there is little point in trying to construct a complete list of fallacies. What is crucial is to get a feel for the most common and most seductive kinds of fallacy.
In a good argument, we present statements that are true in order to offer support for some conclusion. One way to depart from this ideal is to statethings that are true themselves, but have no bearing on the truth of the conclusion.Fallacies of relevance are surprisingly common in everyday life. People often introduce irrelevant details or tangents in order to mislead by divertingattention from the real issue. The irrelevant distraction is sometimes described as a red herring (after a man who dragged a red herring across histrail in order to throw pursuing hounds off his scent). The best strategy for dealing with such tricks is simply to cross out all irrelevant claims and thensee what is left. Sometimes nothing is left.
Literally, an argument ad hominem is an argument directed against a person who is making a claim rather than against that person’s claim or argument forit. On the face of it, this move seems to involve irrelevance, for the character or social position or status of a person should have nothing to do with the truthof what that person says or with the soundness or strength of that person’s arguments. Even when protesters dress shabbily or fail to bathe, their clothingand hygiene show nothing about the legitimacy of their protest. A speaker’s ethnicity, race, sex, or sexual orientation almost never give us any good reasonto challenge the truth of what that person says or the soundness of his or her argument.
Deniers they deny the truth of what is said or the strength or soundness of an argument. Silencers they revoke the right to speak without necessarily denying the truth of what Dismisser point is not to deny the truth of the claim or the speaker’s right to say it. Instead, a dismisser is supposed to show why the fact that this speaker supports a claim is not a good reason to believe that claim (or to deny it, for that matter).
Arguments are vacuous when they don’t go anywhere. This happens in two main ways. Sometimes an argument begins by assuming its conclusion or some independent reason for its conclusion, so the argument makes no real progress beyond its own assumptions. In other cases, the argument’s conclusion is empty, so the argument has nowhere in particular to go. Both kinds of argument are fallacious and vacuous, so we call them fallacies of vacuity.
If the first sentence is supposed to provide a reason for the next three sentences, then those three sentences cannot later be used as a reason for the lastsentence without the whole argument becoming circular, because the last sentence, “Terrorists can’t be stopped without torture,” means pretty much thesame as the first sentence, “The only way to prevent terrorists . . . is to inflict enough pain on them. . . .”
begging the question when its context raises the question of why anyone who denies its conclusion should accept its premisesand when that question has no adequate answer
Someone argues for the pro-choice position simply on the grounds that a woman has a right to control the destiny of her own body,this also begs an important question, because it takes for granted the claim that the fetus is part of a woman’s body, not an independent being with rights of its own.
Before you accuse people of begging the question, you should ask them to give you their reasons for the disputed premise. If they can come up with an independent reason, then they did not beg the question, and you might learn something from them. However, if they do not have any independent reason for the premise, then they did indeed beg the question.
Refuting a charge requires giving an adequate argument against it.Refutations, then, take four main forms: (1) We can argue that some of the premises are dubious or even false. (2) We can argue that the conclusion of the argument leads to absurd results. (3) We can show that the conclusion does not follow from the premises (or, in the case of an inductive argument, that the premises do not provide strong enough support for the conclusion). (4) We can show that the argument begs the question.
One common way to refute a premise by showing that it is false is by producing a counterexample. Counterexamples are typically aimed at universalclaims. This is true because a single contrary instance will show that a universal claim is false.
In response to a counterexample, many people just repeat the misleading saying, “That’s the exception that proves the rule.” What most people do not realize is that “proves” originally meant “tests,” so all this saying means is that an apparent exception can be used to test a rule or a universal claim. When the exception is a true counterexample, the universal claim fails the test.
One method is to show that the claim to be refuted implies something that is ridiculous or absurd in ways that are independent of any particular counterexample. This mode of refutation is called a reductio ad absurdum, which means a reduction to absurdity.
In sum, then, a reductio ad absurdum argument tries to show that one claim, X, is false because it implies another claim, Y, that is absurd. To evaluatesuch an argument, the following questions should be asked:1. Is Y really absurd?2. Does X really imply Y?3. Can X be modified in some minor way so that it no longer implies Y?If either of the first two questions is answered in the negative, then the reductio fails; if the third question receives an affirmative answer, then thereductio is shallow. Otherwise, the reductio ad absurdum argument is both successful and deep.
The general rule is this: Before trying to refute someone’s claim, it is important to make sure that you understand his or her position. Sometimes people attack a straw man intentionally. They mischaracterize their opponents’ position on purpose in order to make their opponents look silly by associating their opponents with a position that really is silly.
In more insidious cases, straw men are often set up by means of a related fallacy—false dichotomy. With regard to the Iraq war, President Bush oftensaid something like this: “I had a choice to make: Either take the word of a madman [Saddam Hussein] or defend America. Given that choice, I will defend America every time.” The crucial phrase, of course, is “given that choice.” If those were the only options, then Bush’s critics would also defendAmerica every time. The problem lies in Bush’s suggestion that his opponents do not want to defend America and would instead “take the word of amadman.” That insinuation sets up a straw man.
Ellery Ivan E. Apolinario
At the end of this discussion, the participants will be
1. Identify an argument.
2. Identify forms of debate fallacies.
What is an argument?
We will view arguments as tools. To understand a
tool, we need to know the purposes for which it is
used, the material out of which it is made, and the
forms that it takes.
For example, what is the purpose of hammers?
Hammers are normally used to drive nails or to
pound malleable substances. Hammers are usually
made out of a metal head and a handle of
wood, plastic, or metal. A typical hammer’s handle is
long and thin, and its head is perpendicular to its
Similarly, in order to understand arguments, we need
to investigate their purposes, materials, and forms.
The number and variety of argumentative fallacies
are limited only by the imagination.
What is crucial is to get a feel for the most common
and most seductive kinds of fallacy.
Once this is done, we should be able to recognize
many other kinds as well.
red herring argument
Sometimes the occurrence of irrelevance is innocent; good
arguments often contain irrelevant information.
Examine two kinds of arguments that
often involve fallacies of irrelevance: arguments ad
hominem and appeals to authority.
argument ad hominem
An argument directed against a person who is
making a claim rather than against that person’s
claim or argument for it.
3 types of argument ad hominem
Deniers - a claim is untrue or that an argument is
unsound or weak
Silencers - conclude that someone lacks the right to
speak in a certain context.
Dismissers - conclude that someone is untrustworthy
Fallacies of Vacuity
Arguments are vacuous when they don’t go
This happens in two main ways.
the argument makes no real progress beyond its own
the argument’s conclusion is empty, so the argument has
nowhere in particular to go.
The only way to prevent terrorists from committing
their horrible crimes is to inflict enough pain on them
either to scare them off or to force them to reveal
information that enables the police to head off
terrorist attacks. Because these are the only
methods that work, we cannot reason with them or
talk them into giving up. We cannot make friends or
sign a treaty with them. We cannot buy them off or
satisfy their demands. Therefore, terrorists cannot be
stopped without torture.
Begging the question
It’s always wrong to murder human beings.
Capital punishment involves murdering human
Capital punishment is wrong.
Begging the question
Opponents of abortion typically refer to the human
fetus as an unborn baby or simply as a baby. It may
seem a matter of indifference how the fetus is
referred to, but this is not true. One of the central
points in the debate over abortion is whether the
fetus has the status of a person and thus has the
rights that any person has. It is generally
acknowledged in our society that babies are persons
and therefore have the rights of persons. By referring
to the fetus as an unborn baby (or simply as a
baby), a point that demands argument is taken for
granted without argument. That counts as begging
Begging the question
Of course, many opponents of abortion argue for the
claim that a human fetus has the moral status of a
person and thus do not beg this central question in
the debate. Still, if they give no such independent
argument, then they do beg the question.
Begging the question
Someone argues for the pro-choice position
simply on the grounds that a woman has a right
to control the destiny of her own body, this also
begs an important question, because it takes for
granted the claim that the fetus is part of a
woman’s body, not an independent being with
rights of its own.
Begging the question
One way for an argument to beg the question is
for it to rely, either explicitly or implicitly, on an
unsupported premise that is a matter of dispute
in the particular argumentative context.
Thus, referring to a human fetus as a baby will
be question begging in contexts in which the
moral status of the fetus is at issue, but it may
not be question begging when this is not an
Begging the question depends in this way on
context, we should be careful before charging
opponents with begging the question
WHAT IS REFUTATION?
To refute an argument is to show that it is no good.
Some writers, however, incorrectly use the term
―refute‖ to mean something much weaker.
A refutation of an argument is sufficient if it raises
objections that cannot be answered.
Consequently, the patterns of successful
refutations mirror the criteria for a good
argument, because the point of a refutation is to
show that one of these criteria has not been met.
WHAT IS REFUTATION?
Refutations, then, take four main forms:
(1) We can argue that some of the premises are
dubious or even false.
(2) We can argue that the conclusion of the
argument leads to absurd results.
(3) We can show that the conclusion does not
follow from the premises (or, in the case of an
inductive argument, that the premises do not
provide strong enough support for the
(4) We can show that the argument begs the
Premises are dubious or even false.
One common way to refute a premise by showing
that it is false is by producing a counterexample.
Counterexamples are typically aimed at universal
claims. This is true because a single contrary
instance will show that a universal claim is false.
Opponent’s reply – ―Exception to the rule argument‖
Reductio ad absurdum
Particular counterexamples can normally be used to
refute claims only if those claims are universal, so
how can we refute claims that are not universal?
Suppose there is a largest integer. Call it N.
Since N is an integer, N + 1 is also an integer.
Moreover, N + 1 is larger than N.
But it is absurd to think that any integer is larger than
the largest integer.
Therefore, our supposition—that there is a largest
integer—must be false.
In sum, then, a reductio ad absurdum argument
tries to show that one claim, X, is false because
it implies another claim, Y, that is absurd. To
evaluate such an argument, the following
questions should be asked:
1. Is Y really absurd?
2. Does X really imply Y?
3. Can X be modified in some minor way so that
it no longer implies Y?
If either of the first two questions is answered in
the negative, then the reductio fails; if the third
question receives an affirmative answer, then the
reductio is shallow. Otherwise, the reductio ad
absurdum argument is both successful and
Straw men and false dichotomies
Attacking a claim that isnt there is called ―attacking a
In 2004 presidential election, when John Kerry
suggested that the United States should have
conferred more with its allies, including the
French, before attacking Iraq. In response, at the
Republican National Convention Senator Zell Miller
said that Kerry would ―let Paris decide when America
needs defending.‖ Surely Miller knew that this
mischaracterization of Kerry’s position was
unfair, but it achieved the desired reaction from the
In more insidious cases, straw men are often set
up by means of a related fallacy—false
Sinnort-Armstrong, W and R. Fogelin. Understanding
Arguments: An introduction to informal logic, 8th