III. Rhetorical Situation

3.6 Logical Fallacies

Melanie Gagich; Emilie Zickel; and Terri Pantuso

As previously noted, using ethos, pathos, and logos in an argument does not mean that the argument made is necessarily a good one. In academia, especially, we care a lot about making our arguments logically sound; we care about logos. We seek to create work that is rooted in rational discourse. We seek to produce our own rational discourse. We value carefully researched, methodically crafted work. Thus, to be a strong academic writer, one should seek to avoid logical fallacies, which are flaws in reasoning.

To refer to something as a fallacy means to say that it is false. Think of the concept of a logical fallacy as something that makes an argument problematic, open to attack, or weak. In academic discourse, logical fallacies are seen as failures – as things we want to avoid.

Thinking about fallacies can be confusing because we see them all the time: in advertising, in conversation, in political discourse. Fallacies are everywhere. But as students of rhetoric, part of our job is to spend time identifying these fallacies in both our own writing and in others’ as a way to avoid them.

Table 3.6.1 contains a partial list of logical fallacies.

Logical Fallacies – A Partial List
Hasty Generalization A conclusion or judgement made from insufficient evidence. When one piece of evidence or information is used to make a broad conclusion or statement.
Cherry Picking Picking and choosing only some of the available evidence in order to present only points most favorable to your point of view. If someone knowingly chooses certain (favorable) pieces of information and conveniently ignores less favorable information, then the argument is not supported by all of the available research.
Straw Man An oversimplification of an opposing perspective so that it becomes easy to attack. This is unfair and illogical because when one oversimplifies or inaccurately represents an argument and refutes that oversimplified version, one is not actually addressing the argument.
Red Herring Changing topics to avoid the point being discussed. This is an argument tactic in which one attempts to change the conversation, often by bringing up information that is not relevant to the claim or point being debated, in order to try to control the conversation. This can be a way to avoid having to address or answer the question at hand, and it harms the quality of an argument.
Ad Hominem Making a personal attack rather than engaging with someone’s ideas such as the following: “You are an idiot! That’s why you’re wrong!” This type of logical fallacy occurs when an arguer attacks or insults the person making opposing arguments instead of attacking the ideas, the logic, or the evidence within the opposing argument itself.
Ad Populum Making an argument solely based upon the perceived shared beliefs of a group such as the following: “This is about freedom and righteousness, and if you believe in those things, then you should believe my argument.” This is an example of misused ethos – when the author is referencing the values that the audience cares about so that they think only about the values and not about the content of the argument (or, likely, the fact that there is little intellectual substance in what is being said).
False Dilemma, Either/or This is an argument that attempts to create a situation of absolutes with no options in between such as the following: “Either we intervene or we are basically no better than the Nazis.” This thinking is fallacious because it assumes that there are only two options, with nothing in between.
Slippery Slope This is a fallacy that assumes that one thing is going to have a series of consequences or effects–often leading to a worst case scenario such as the following: “If we let this happen, then that will happen and then the worst possible thing will happen.” It is false reasoning because 1) it’s impossible to predict the future, 2) it is illogical to suggest that one action will always necessarily lead to the worst possible outcome, and 3) it assumes a very specific chain of future events. This “if we let this happen there will be some horrible end” is a misuse of cause/effect reasoning, often with some pathos (fear) sprinkled in.
Bandwagon This is a fallacy that assumes one will follow the crowd, sort of by peer pressure. Consider the old adage “Everybody’s doing it!” The problem with this type of fallacy is that it assumes the reader/listener will only follow the crowd and not exercise free thought.
False Authority This fallacy attempts to use credentials of one to support another claim even when those credentials are not valid for the argument at hand such as the following: “Because X says it’s true, it must be true!” For example, someone with a PhD in music theory might know a great deal about genetically modified foods based upon readings; however, citing that person as an expert in the field would be a fallacy.
Dogmatism This fallacy relies on the assumption that the truth is self-evident and needs no further explanation such as the following: “Global warming is real because polar bears are dying.” This line of reasoning is often aggressive and invasive. Someone relying upon this tactic refuses to hear the other side.
Stacking the Deck This fallacy is used when only one line of reasoning or evidence is used to support a claim/argument. When used, this fallacy ignores oppositional reasoning or counterevidence.
Post Hoc, Ergo Propter Hoc This is a Latin phrase that means “after this, therefore because of this.” This means that someone makes a claim that one event caused another, when it is instead a correlation. An extreme example of this might be someone claiming that the sunrise causes people to brush their teeth, just because many people brush their teeth in the morning.
Begging the Question This fallacy occurs when the speaker assumes that the conclusion of his/her argument is valid without proving the lines of reasoning. Many times, the support used for the claim is simply a repetitious restatement of the conclusion. Oftentimes, this type of argument feels circular or redundant.
Equivocation This fallacy relies on the ambiguous use of a key term within the argument thereby misleading the reader/listener. An example might be the use of the term “undocumented workers” to signify persons who are not citizens of a country yet work/live in a country. Oftentimes, equivocations rely on half-truths that give the illusion of an honest overall appearance to the argument.
Non Sequitur (it does not follow) This fallacy skips or confuses logical steps thereby making an argument appear to be hollow. The result is often a conclusion that does not follow from the evidence provided.

Table 3.6.1. Logical Fallacies – A Partial List

When reading or listening to an argument, be cognizant of when the reasoning relies upon one of these fallacies of logic. If it does, question the source and the information presented carefully.

As you draft ideas for your own arguments, test each of your reasons/claims against these definitions. If you find that you have used any of these fallacies to build your argument, revise for clarity.

Exercise

Select five (5) of the logical fallacies presented above and write an example for each. Then, in a brief statement explain the nature of the fallacies you have written.

This section contains material from:

Gagich, Melanie and Emilie Zickel. “Logical Fallacies.” In A Guide to Rhetoric, Genre, and Success in First-Year Writing, by Melanie Gagich and Emilie Zickel. Cleveland: MSL Academic Endeavors. Accessed July 2019. https://pressbooks.ulib.csuohio.edu/csu-fyw-rhetoric/chapter/logical-fallacies/. Licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

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3.6 Logical Fallacies Copyright © 2022 by Melanie Gagich; Emilie Zickel; and Terri Pantuso is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.