Some Logical Fallacies
What is a fallacy?
A fallacy is “a serious and identifiable defect in an argument”. (Fulkerson, 1996:96)
“A fallacy is an argument that is flawed by irrelevant or inadequate evidence, erroneous
reasoning, or improper expression.”(Inch and Warnick, 2002:33)
There are many ways to categorise fallacies, one of which is as follows:
(A) Fallacies of faulty reasoning
(B) Fallacies of evidence
(C) Fallacies related to audience
(D) Fallacies of language use
(A) Fallacies of faulty reasoning
1.
False Analogy. This fallacy arises because the arguer either highlights trivial similarities
or ignores and downplays important differences, when drawing parallels between two
entities/ phenomena.
2.
Over-generalization / Fallacy of Accident. This fallacy results from insensitivity to
special cases, when an abstract principle is inappropriately applied to a specific
circumstance. It involves a failure to consider rebuttal conditions, when applying a
general principle.
Example
Using the general principle “you can put out a fire by throwing water on it”, one might
overgeneralize that all fires can be put out by water. Applying this principle to gasoline
fires, which represent a special case, would lead to the fallacy of accident/
overgeneralization, since the general principle does not apply to this specific type of
fire.
3. Post hoc, ergo propter hoc (Latin for “after this, therefore because of this”). This fallacy
involves mistaking temporal sequence for causal sequence.
Example
The cock crows. Then, the sun rises. Therefore, the sun rises because of the cock’s
crowing.
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4.
Single Cause. This fallacy occurs when an arguer attributes only one cause to a complex
problem. This fallacy might be seen as an instance of oversimplification, i.e., reducing
the complexity of the causal generalisation to be drawn. Often, this results from a lack
of qualifying conditions or limits on the generalisation being made.
Example:
Singapore’s woes derive from its lack of natural resources.
(Note: When propositions are made, if a qualifier is not present, the default
interpretation tends to be that the assertion is being made about all or most of the
members of the population)
5. Either-or thinking / False Dilemma. Like oversimplication, this fallacy results from
polarized thinking, which involves attending to extremes, and not thinking about inbetween states. This fallacy is sometimes referred to as black / white thinking, because
of a refusal to acknowledge the many shades of grey in life.
Example
We either teach filial piety at a young age or prepare fort parents to end up on the
streets, in their old age.
Clearly, there are a host of possibilities in between these two extremes presented
here.
6. Mistaking correlation for causation. When investigators notice a correlation between
two phenomena, they commonly ask whether there is a causal connection underlying
the correlation. But, this causal mechanism cannot just be assumed. Rather, it needs to
be demonstrated.
Example
Violent crime increases when the temperature increases.
There is a correlation here. But, is there also a causal connection between crime and
temperature?
7. Slippery Slope. The slippery slope fallacy associated with reasoning about causation
occurs when an arguer claims that an innocent-looking step first should not be taken
because it will ultimately lead to bad consequences, without providing justification as to
how/ why the bad consequences will result. The assumption underlying the slipper slope
fallacy is that while the first step down the slope may be tempting, once the first step is
taken, it will be difficult or impossible to stop the slide, and disaster waits at the bottom.
Example
If you legalize marijuana, more people will start puffing it, and then move on to
cocaine, and wind up hopeless and homeless and hardened heroin addicts.
The arguer provides no justification as to how/ why the first step will lead to the
consequences asserted above.
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(B) Fallacies of evidence
1. Non sequitur (it does not follow) The conclusion does not follow from the argument.
Example
The Bell Curve is theoretically sound because it was on the New York Time’s Top Ten
List. (being on the top ten list has nothing to do with theoretical soundness).
The red herring fallacy (the name comes from the practice of throwing a red herring in
front of hunting dogs so as to throw them off the scent/trail) is an instance of the non
sequitur fallacy.
2. Begging the Question is the fallacy of appealing to a principle that is in question as
though it were already settled. It is a kind of circular argument in which the conclusion
appears in the premise(s) in slightly different words.
Examples
The incest taboo is instinctive because humans are genetically programmed to abhor
incest. Here the term instinctive is equivalent to the term genetically programmed, so
we’re arguing in circles.
You need a sense of humour to be happy because happiness depends on being able to
see the funny side of things.
(If we understand a “sense of humour” as the ability to see the funny side of things,
we can see how this argument is circular, since a sense of humour appears both as
premise and conclusion).
(C) Fallacies related to audience
1. Straw argument. The fallacy involves a deliberate misrepresentation of an opponent’s
argument so as to make refutation of it easier. The straw argument comprises
exaggerating and caricaturing, i.e., presenting a weaker, or, distorted version of an
opponent’s argument, then proceeding to attack the exaggerations and caricatures,
while ignoring the merits and complexities of the original position.
Example
The feminist movement asserts that…
Whenever you see the article “the” in front of a group label, ask yourself whether
there is such a monolithic and homogenous group. Straw arguments typically
oversimplify complex positions/ belief systems.
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2. Argumentum ad hominem. (attack against the person) It occurs when an arguer
responds to a co-arguer’s argument by attacking the person instead of the argument
presented.
Example
A is arguing for increased welfare benefit. And, B responds “Are you going to take
the advice of a man who used to beat his wife and has an ongoing substance-abuse
problem?”
3. Argumentum ad populum (To the people) The arguer appeals to the prejudices/fears of
the people and considers this sufficient to settle the issue. See section 4, for more on
this fallacy. The bandwagon device – arguing that you should do X because lots of people
are doing X – is an instance of argumentum ad populum.
4. Argumentum ad misericordiam (Latin for “appeal to Pity”) Using sympathy to advance a
contention; fallacious if, and only if, the premise is logically unrelated to the claim made.
5. Argumentum ad ignorantium (from ignorance) Because a premise is not currently
known to be false, it is maintained that it is therefore true.
Example
There is no proof that flying saucers don’t exist. Therefore, they exist.
(D) Fallacies of language use
1. Equivocation is a fallacy arising from semantic ambiguity. This ambiguity can be lexical
or referential. Lexical ambiguity results because lexical words can have multiple,
unrelated meanings.
Examples
A person can have a germ of an idea. Germs cause disease. Thus, ideas cause disease.
The word “germ” has two distinct meanings – it can refer to seeds (as in germ of an
idea) or to microscopic disease-causing entities. The arguer above, however,
conflates the two meanings, using them interchangeably, thereby committing the
fallacy of equivocation.
Science has an ethical obligation to focus on matters of public interest. The public has
an interest in UFOs. Therefore, science has an ethical obligation to focus on UFOs.
The term “public interest” has two distinct meanings: In the first premise, it means
“public welfare”. In the second, it means “popular diversion”.
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Referential ambiguity arises when there are two or more possible referents for a
pronoun, and it’s unclear which the pronoun refers to.
Example
The anthropologists went to a remote village and took photographs of the children –
they weren’t developed.
Who does the pronoun they refer to – the photos or the children? This is a common
problem, so watch out for it in your own writing.
2. Amphiboly is a fallacy arising from syntactic ambiguity, i.e., sentence/phrasal
constructions that produces a double meaning.
Example
I’m having some friends for dinner.
Are the friends the Subject or the Object of the verb “eat” – who or what is going to
get eaten? Amphiboly can be disambiguated through paraphrase, e.g. I’m having some
friends over for dinner. I’m inviting some friends to dinner.
3. Accent is a fallacy arising from false emphasis, i.e., emphasis on the wrong word,
conveying a false impression.
Example
This snake can only eat frogs.
The position of “only” creates a false contrast between eating frogs and doing other
things with frogs. Cf. This snake can eat only frogs, where “only” is positioned correctly
to create a contrast between frogs and other things that might be eaten.
Bibliography:
Barry, Vincent. Good Reason For Writing: A Text with Readings. Belmont, CA: Wadsworth.
Corbett, Edward P. J. 1990. Classical Rhetoric for the Modern Student. 3rd ed. New York:
Oxford UP.
Fulkerson, Richard 1996. Teaching the Argument in Writing. Illinois: NCTE.
Inch, E.S. and B. Warnick. 2000. Critical Thinking and Communication: The Use of Reason in
Argument. 4th ed. Boston: Allyn and Bacon.
Kahane, Howard. 1980. The Nature and Classification of Fallacies. In J. Anthony Blair and
Ralph H. Johnson (eds.), Informal Logic: The First International Symposium. CA:
Edgepress. 31-40.
Lee, Alfred McClung, and Elizabeth Briant Lee. (1939) 1972. The Fine Art of Propaganda.
New York: Harcourt. Rpt San Francisco: International Society for General Semantics.
Miller, Clyde R. 1939. How to Detect and Analyze Propaganda. New York: Town Hall, Inc.
vos Savant, M. 1996. Chapter 3: Misunderstanding Statistics. The Power of Logical Thinking:
Easy Lessons in the Art of Reasoning…And Hard Facts about its Absence in our Lives. New
York: St Martin’s Press.
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