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CMN-504: Introduction to Argumentation
Informal Patterns of Reasoning
& Practical Argument Fallacies
ARGUMENTS RELATED TO THE CATEGORY OF “BEING”:
Argument from Definition: This argument advances a claim that a particular object, person, action, or idea
belongs to a certain class or category. The argument begins with a clear definition of a class or category of persons,
things, ideas, or actions. The definition is taken from public knowledge (what is generally accepted and known), or
it is established on the basis of some authoritative source (a law book, dictionary). Once the definition is agreed
upon it is then applied to particulars — to the specific case at hand. When the particular case is shown to fit the
definition, the conclusion is drawn that the particular belongs to the class or category named by the definition.
Argument from Division: This way of classifying a particular examines its parts. We begin with some common
sense understanding of the various aspects, qualities, marks, or characteristics of a class or category. These are
enumerated. Then we move to an examination of the parts of the particular. When the number and quality of the
parts match the description of the class or category the conclusion is drawn that the particular belongs to that class.
The argument may also be used to show that a particular does not belong to a class or category.
Dissociation Argument: This argument must begin by taking note of the existing value system in a given
community, and in particular, the priority that is at least temporarily given to one value over another when those
values come into conflict. The dissociation argument is recognized because it starts by constructing an opposition of
perspectives. Two or more ways of viewing a problem or judging an issue are suggested. Both perspectives may
have merit, but one is more important, more relevant, or more valuable in this case than another. The argument
advances by the privileging of that one perspective over another. This (often implicit) value claim should reflect
some aspect of the shared values of the community (although sometimes the arguer will also have to give reasons for
the value hierarchy he or she proposes.) After suggesting one perspective as the most important, the arguer will then
draw a conclusion consistent with that perspective (and with the implied values of the community). Because it is
based on an opposition, often such arguments will use an antithetical structure (such as: “on the one hand . . . but on
the other hand . . .”). And, these arguments tend to invoke one from among a set of commonplace comparisons
(e.g.: “in the short term . . . but in the long term . . .” or, “the letter” vs. “the spirit” of the law). Other commonplace
oppositions include: honor v. expedience; natural vs. artificial; new vs. old (traditional); science vs. ethics;
environment vs. economics, and public vs. private. We include this form of argument in the category of “being”
because in requires us to choose the relevant perspective that allows us to properly “name” or define a fact or event
about which we are arguing and which we then are able to correctly judge. By choosing the proper perspective from
which it should be judged we are able to identify the class or category to which the fact or event properly belongs.
Generalization: Generalization arguments begin with evidence drawn from a sample. We test a “sample” and
obtain some “data.” The sample is part of a “target population.” The argument advances a claim that says the data
or “projected property” discovered in the sample will likewise exist or be true in the “target population.” We test a
generalization argument by asking whether the sample is “representative.” To be representative, we must judge its
size, its randomness, and its, spread. We judge of size by measuring the sample size in relation to the size of the
target population. We judge of randomness by asking simply whether every member of the target population has an
equal chance to be included in the sample. We judge of spread by asking whether the sample includes all the
important differences that might make a difference in the data. For example if the target population is University
students, a sample should have men and women, commuters and dorm students, freshmen, sophomores, juniors, and
seniors, Liberal Arts and CEPS students, etc. When a projected property is a causal claim, then we have a causal
generalization, and tests for generalization and casual arguments both apply. Most medical research studies are
causal generalizations (see below).
Hasty Generalization: a fallacy that results when a general claim is not warranted because the sample is
biased, or not representative.
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Example: Aristotle’s inductive@ argument. Argument by example is a generalization argument that uses a
sample of one, or a small number of representative cases.
Transitivity Arguments (quasi-logical): Within logic, “transitivity” refers to the way that we understand the
relationship between two things (two terms) because we know how each is related to a third thing. Using this
reasoning process I can determine what a thing is (being) indirectly. Thus, if I know you are John’s brother, and I
also know that Mary is John’s mother, then I can conclude that Mary is also your Mother. In the transitivity
arguments we employ reasoning that is like that used in the deductive syllogisms of formal logic. However, unlike
the syllogisms they imitate the transitivity arguments are not dependent on formal rules of logic. Rather, they rely
on our natural reasoning ability to recognize the logical implications of the known relationships between three
different terms. Thus, if I know that Roger is a Red Sox fan, how can I possibly conclude that Roger is a beer
drinker? I can do that sensibly if I also know that all (or most) Red Sox fans drink beer. Aristotle would call such
arguments “rhetorical syllogisms” or enthymemes. Usually, in this kind of argument, one of the premises relates to
known particulars (Roger is a Red Sox fan), and the other is a widely held belief or a “truth” widely shared. Often
that widely-held “truth” remains implicit (unstated) and is filled in by the mental reasoning process (inferencemaking) of the recipient of the argument.
Hypothesis: This sort of argument aims to offer an explanation of observable facts by supplying a theory that
explains the facts. We begin with a question regarding the meaning of—or the proper classifying of—a set of facts.
The meaning of those facts is disputed or unclear. There might be several possible explanations. The hypothesis
argument is made in support of one of the explanations. To test the reliability of any hypothesis—that is, to see if
the explanation is warranted—we need to apply three criteria: 1. Accountability: you must ask whether the
hypothesis can explain, account for, all of the facts in question. 2. Simplicity: you must ask whether the hypothesis
advanced is the simplest explanation that can account for the facts (or does it rather go beyond the facts to construct
a plausible explanation?). 3. Frequency: you must ask whether the hypothesis is the most frequent actual
explanation in like cases (involving, then, some attention to “similarity”—see below).
Far-Fetched Hypothesis: If a given explanation fails one or more of these tests, it may still be true, but to
the degree that it is therefore less probable (or unwarranted) we would define it as a Far-fetched
Hypothesis.
ARGUMENTS RELATED TO THE CATEGORY OF “CAUSE”
Co-existential Arguments: This is Aristotle’s “Argument from Sign.” The claim affirms something about an
unseen condition or fact on the basis of some associated observable fact or condition. The inference is based on a
general understanding that the visible “effects” are “signs” of the invisible cause or condition. Medical diagnosis,
for example, is based on co-existential reasoning. The presence of a symptom is a “sign” of (or it usually co-exists
with) an underlying disease.
Causal Explanation: Like the Hypothesis argument, this argument advances a claim that explains a set of facts or
observable data. However, it is different in that it offers a specifically causal explanation. It is, then, an argument
in support of causal (relational) claim. The argument asserts that one fact or condition or event is the cause of
another. To test causal arguments you should apply the tests of necessary and sufficient condition: Is the alleged
cause necessary to produce the effect? Is the alleged cause sufficient to produce the effect? One can also test causal
arguments by looking for negative cause cases and negative effects cases. Negative cause cases are instances where
the alleged result is present without the cause. Negative effects cases are instances where the alleged cause is
present but does not produce the effect. When the claim of a causal argument is not warranted, the argument
commits one of several fallacies.
A. False Cause: When it is clear that the alleged cause is not necessary to produce the effect, and when
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you find there are a number of negative cause cases and/or negative effects cases.
B. Single Cause: When it is clear that the cause is more complex than the explanation offered. The
fallacy is revealed by the test of sufficiency. Is the alleged cause alone sufficient to produce or account for
the effect?
C. Post Hoc Ergo Propter Hoc: Literally “after this therefore because of this,” the fallacy is revealed by
application of the test of necessity, or by the presence of significant number of negative cause and negative
effects cases. The fallacy occurs when the arguer makes the specific mistake of seeing chronological order
as logical order. That is, the apparent correlation between alleged cause and effect is the result of proximity
in time, rather than any evidence of a causal relationship.
Causal Generalization: When a causal explanation is generalized, then the argument is a causal generalization. In
such an argument the “projected property” of a generalization is a causal claim. In other words, the causal claim is
proven or probable in the sample, and then that same causal relationship is “generalized” to a target population. (in
the sample, A led to B, so therefore A will lead to B in all, or most, cases). The argument is “generalized” when the
causal claim is asserted to be true (the relationship maintains) in any case where the alleged cause and effect are
present. One can test the causal generalization by applying the proper critical assessments for both causal
explanation and generalization arguments.
ARGUMENTS RELATED TO THE CATEGORY OF “SIMILARITY”
Argument by Analogy: This is one of the commonplace argument forms included among Aristotle’s general
topics. Analogies are fundamentally based on perceived similarities. We reason about a particular case by drawing
on our understanding or common knowledge of another particular case with similar properties, qualities, or marks.
To test whether a claim based on argument by analogy is warranted or not we want to know if the comparison is
justified. We should ask: what are the similarities? Then, we should apply tests of quality and quantity: Are they
the most important features or qualities being compared? Are there enough similarities to suggest the two particular
cases truly belong to the same class?
A. Literal Analogies compare two things or events from the same class or category. Literal analogies can
be used as evidence for a claim if the analogy is warranted.
B. Figurative Analogies compare things or events from different classes or categories. While figurative
analogies can be illustrative and aid persuasion, they have no force as evidence, and cannot be
warranted. An example of a figurative analogy would be the extended metaphor that sees the rise
and fall of the stock market as “a roller-coaster ride.”
C. False Analogy: If the comparison suggested by the literal analogy is not warranted, because the
similarities are not important or are insufficient in number, the argument is flawed, and commits
the “false analogy” fallacy.
Argument by Degree. This is another of Aristotle’s general topics. The argument is sometimes called the “superanalogy” or the a fortiori argument. Like an analogy, it compares two particular cases. A claim is made about the
probabilities associated with one case based on another known case where the outcome is less probable. Since the
less likely thing is known to have occurred, the case under investigation is considered to be very likely. If the
poorest student in the class got an “A” on the exam, how much more likely is it that the best student got an “A”?
Reciprocity Arguments (quasi-logical): This argument is based on the universal principle of equity. We presume
that persons, events, facts of equal status will be treated equally. When that does not occur, we recognize a violation
of the principle of equity. We might typically say “that’s not fair.” An argument that is based on the principle of
equity may point out the similarity between like cases, and so connects to the category of “similarity.” However,
unlike the argument by analogy, there is here a specific moral concern with the justice (or injustice) of equal (or
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unequal) treatment of the two like particulars.
COMMON ARGUMENT FALLACIES
Slippery Slope Fallacy: A very common reasoning error which is based on the assumption that if we take one step
in a policy plan (which might itself be quite reasonable) we must inevitably follow with all the other steps that lead
to an eventual disaster. For example, some might argue against the medical use of marijuana because it is merely
the “first step” toward total legalization of dangerous drugs. There is no natural, unstoppable progression which
necessarily follows from any policy choice. If we are reasonable people, we can do what is right, and make the
decision not proceed to any further step which would be undesirable. Just because we wish to ban private
possession of assault weapons, does not mean we must or will then necessarily proceed to the banning of hunting
rifles or target pistols.
Appeal to Tradition: This is New Hampshire’s favorite argument, and is a common fallacy of conservative
discourse. It affirms the value of the past as sacrosanct, rejecting any policy that alters or changes “the way we’ve
always done things.” It is true that there is a natural presumption in favor of the status quo, but the mere existence
of a tradition is insufficient evidence to reject a reasonable policy that has been advanced on the basis of good
evidence. Again, remember that at one time it was “traditional” for women not to work outside the home, and
“traditional” for country clubs to deny admission to racial and religious minorities.
Ad Populum Fallacy: This is the appeal “to the people,” and another common fallacy in which support for a claim
is taken from “what everyone wants” or “what most people do.” The argument assumes that because everyone or
most people want something, that it is therefore the right thing to do. Such arguments are sometimes useful, but are
seldom convincing on their own, providing insufficient grounds for accepting or rejecting a policy proposition.
Such an appeal does not consider the merits of the policy itself, nor the evidence offered for or against it.
Remember that at one time, most people thought it was a good idea that only men vote, that we have segregated
schools, that we don’t permit Catholics to hold public office, and the like. A good example of the “ad populum”
fallacy was President Nixon’s invocation of the “great silent majority” of Americans. Not only did Nixon make the
appeal to the people, but he assumed that those who had not expressed their opinion at all were by virtue of that
silence, on his side.
Ad Hominem. Like the Ad Populum fallacy, the fallacy of Ad Hominem does not consider the merits of the policy
being debated, and so provides no strong grounds for a claim against it. Rather it only considers the character,
associations, words, or actions of those who promote or advance the policy. Literally it is an argument directed “at
the man” rather than at the policy. “We shouldn’t support Senator Kennedy’s gun control policy, after all, he’s been
the most liberal Democrat in the Senate for more than 40 years.” Here the rebuttal to the policy is directed, not at
any flaw in the plan itself, but at the person responsible for advancing that plan.
Straw Argument: This argument is almost always used in attack or rebuttal. Like the forms above, it makes the
reasoning error of supporting a claim with very insufficient evidence. The straw argument fallacy (sometimes called
the “strawman”) works by focusing on one questionable or weak or doubtful aspect of a policy which it opposes.
Usually the focus is on a relatively unimportant or minor flaw. However, that flaw it taken to represent – as if by
synecdoche – the entire policy, and a rejection is recommended on the basis of that flaw. “The new dining hall
menu provides only one vegetarian option on Tuesdays. It doesn’t matter that the menu has won national gold
medals, we should demand that it be replaced by a menu more sensitive to the needs of the vegetarian community.”
In another variation, the straw argument misrepresents (usually by hyperbole) the position of an opponent so that the
now-exaggerated position is easier to attack. “Republicans only want to help their cronies in the wealthiest one
percent, so you should vote for Democrats.”
Non Sequitur. This Latin phrase means literally “does not follow.” Here an error in reasoning is made when the
“evidence” advanced in support of a claim is actually irrelevant to the claim. The argument lacks “inherency”—that
is, the truth of the claim is not “inherent” in the evidence. As such, the evidence cannot support the claim because
no inference is possible. The claim “does not follow” from the evidence. So, for example, suppose a fraternity
brother should say to a pledge, “you should rush IOTA OMEGA because the football team is playing Arkansas State
on November 13th.” We would be unable to see any connection here. The reason for rushing IOTA OMEGA would
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not be inherent in the scheduled football game. Usually the mistake is more subtle than this example, and the claim
is usually advanced because the arguer sees some connection (although not a logical one) between the claim and the
alleged evidence.
Begging the Question: This fallacy occurs when an arguer assumes that a debatable question has already been
answered or resolved. Such an argument assumes that one point of contention is in fact not contested at all. As a
result, the conclusion of the argument is based on “evidence” that really does not have the status of evidence,
because it has not been accepted or established as true. For example, if a campus activist argues that “widespread
rape culture on campus proves the necessity of closing the fraternity system.” We would ask (because the question is
begged): IS there, in fact, a “widespread rape culture on campus?” Very often the Question Begging fallacy is
evident in circular arguments, those arguments that assume the truth of a conclusion in stating a premise the purpose
of which is to prove the conclusion that has already been assumed. For example, suppose a professor says: “I cannot
teach logic to these students, for they have no logical abilities. Their SAT scores show they are deficient in logic.”
This claim begs the question “WHY are the students deficient?” The answer, of course, is that the students have not
yet been taught logic, so the objections of the professor are groundless.
Equivocation: This is a language fallacy that comes from not maintaining a stable meaning of terms in the
argument. When an arguer equivocates (“Equal Voices”) he or she proposes two or more meanings for the same
key term within the same argument. As the meaning shifts, then, the arguer exploits the ambiguity in meaning to
advance a claim on the basis of the meaning he or she prefers. “I’m in favor of the ‘Family Protection Act.’ I think
all families need protecting. The family of my gay neighbors, especially, need protecting from homophobic bigots
who don’t see the legitimacy of families that challenge the traditional paradigm of the white suburban heterosexual
family.” Here, of course, the key word is “family,” and the meaning shifts from the use in the title of the legislation,
meant precisely as a defense of traditional marriage and family against the encroachment of gay “marriages” to a
wider, almost opposite notion of family that includes the very concept of “family” that motivated the act in the first
place.
Emotive Language: This fallacy would have us respond emotionally to the language used instead of weighing the
evidence advanced in support of, or against, a claim. Most of the so-called “sentencing” hearings that allow victims
of crime and their families to vent their anger and seek sympathy for their loss tread along the border of this fallacy.
Emotion can be an important element of persuasion (so thought Aristotle), but the point here is that there is a
reasoning mistake whenever a decision is encouraged on the basis of emotional language alone without
consideration of any substantive evidence.
CMN-504: Introduction to Argumentation
Exercise 9
Identify the type or form of argument or fallacy related to Cause in each of the following examples:
1. The student had blood-shot eyes, craved snack foods, emitted a sweet herbal aroma, and failed a short-term
memory test. It is clear that she was abusing Marijuana.
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
D. False Cause
E. Causal Generalization
F. Post Hoc Ergo Propter Hoc
2. If we allow the introduction of sex education to the public schools, students will soon experiment with
sexual activity, the school nurse will be handing out birth control, and school authorities will be
usurping parental authority on all manner of moral issues. To preserve parental rights, we must
stop sex education in the schools.
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
D. False Cause
E. Argument from Consequence
F. Post Hoc Ergo Propter Hoc
3. Studies have shown that the test group of 400 Hispanic and Asian adults given the new COVID-19 vaccine,
not only had fewer instances of the disease, and with less severity, but also slept better and had
fewer common colds than the control group. It seems we finally have the breakthrough we’ve
been waiting for. The government is ready to approve distribution of the vaccine to the general
population soon.
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
D. False Cause
E. Causal Generalization
F. Post Hoc Ergo Propter Hoc
4. The cause of the financial difficulty at the Whittemore Center is clear, concession prices are way too high.
Last night at the women’s hockey game, I paid $8.50 for a piece of pizza and coke. At these
prices, they cannot be selling enough to pay the debt on the arena. If they went back to Snively
era prices–50 cents for popcorn, remember that? I’m sure the red ink would disappear!
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
E. Causal Generalization
D. Single Cause Fallacy F. Post Hoc Ergo Propter Hoc
5. Since the repairs were done on the heating system in the building, several employees have had to leave work
early with flu-like symptoms. I think they had a toxic reaction to chemical fumes emitted from the
newly repaired heating system.
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
D. False Cause
E. Argument from Consequence
F. Post Hoc Ergo Propter Hoc
6. History will show that the collapse of the Soviet Union was due entirely to the determination of Ronald
Reagan to increase American defense spending and pursue the Strategic Defense Initiative. The
Soviet economy simply could not compete in the arms race.
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
E. Causal Generalization
D. Single Cause Fallacy F. Post Hoc Ergo Propter Hoc
7. Since he accidentally spilled his Leinenkugels beer in the garden last week, the rose bush has bloomed
beautifully. He has decided to use a regular application of Leinenkugels to improve his chances at
the county fair rose competition this year.
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
D. False Cause
E. Causal Generalization
F. Post Hoc Ergo Propter Hoc
8. Permitting you to make-up the missed quiz because of the unfortunate death of your great-grandfather would
not be practical. Soon, another student will have a sick neighbor, then it will be a lost cat, and the
next thing you know, I’ll be expected to give make-up quizzes just because the weather is bad.
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
D. False Cause
E. Causal Generalization
F. Post Hoc Ergo Propter Hoc
9 Any effort to lower admission standards for UNH will lead to larger classes, a watered-down curriculum,
grade inflation, academic atrophy, and social decay. We must stop the decline of the University
before it begins.
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
D. False Cause
E. Causal Generalization
F. Post Hoc Ergo Propter Hoc
10. The raising of eligibility standards for Government food assistance must be opposed, for it will lead directly
to increased malnutrition among poor children, and increased hunger even for the working poor.
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
D. False Cause
E. Argument from Consequence
F. Post Hoc Ergo Propter Hoc
11. Studies have shown that the test group of 1100 Canadian university students served Earl Grey tea before
exams, scored on average 13 points higher than the control group who had no beverage within an
hour of test taking, and 8 points higher than those who were served coffee. It is clear that students
everywhere should partake of a relaxing cup of Earl Grey right before exams.
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
D. False Cause
E. Causal Generalization
F. Post Hoc Ergo Propter Hoc
12. The cause of the disparity in GPA between men and women on campus is clear. The majority of full-time
faculty are male, and like gentlemen they are less demanding and more forgiving of their female
students. As a result, female students get higher grades from male professors.
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
D. False Cause
E. Causal Generalization
F. Post Hoc Ergo Propter Hoc
13. I’m in favor of raising the academic standards for UNH admission, since higher standards will improve the
reputation of the University, which in turn will bring more talented faculty and more grant money.
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
D. False Cause
E. Argument from Consequence
F. Post Hoc Ergo Propter Hoc
14. He disputes even commonsense statements, debates with strangers about trivial matters, contradicts
conventional wisdom for recreation, and argues with authority for the adrenaline rush. It is clear
he suffers from that rare disease Argumentationem Extremis. This is a condition is only
exacerbated by his acute Guinness deficiency.
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
D. False Cause
E. Argument from Consequence
F. Post Hoc Ergo Propter Hoc
15. The visiting professor carried a union card, participated in job actions, and even encouraged her students to
read famous pro-labor speeches. It is clear she is a union supporter.
A. Co-existential (sign)
B. Slippery Slope
C. Causal Explanation
D. False Cause
E. Causal Generalization
F. Post Hoc Ergo Propter Hoc