Fallacies

Logical arguments, while sometimes positioned as the purest form of persuasion, can fall victim to a variety of shortcomings. For example, if a generalization in deductive reasoning is incorrect, then the conclusion can be logical but also incorrect. Likewise, fallacies are statements that sound reasonable but are founded in some inaccuracy or assumption that renders the argument untrue or invalid.

Fallacies appear often in arguments. Because they are rooted in logic, they can have the effect of persuading an audience. However, if the audience is paying close attention they will be able to identify and disregard a false line of reasoning. When detected, fallacies in an argument convey a sense of deception or naivety in the Speaker, both qualities to be avoided in effective communications.

Some common fallacies are listed here and divided into different categories. There are many more that influence arguments both serious and trivial every day. Many fallacies have both formal Latin and colloquial names. They are more often referred to using colloquial terms, but some are often referred to using their Latin name, e.g., an ad hominem attack.

Fallacies of Relevance

These fallacies present evidence irrelevant to the argument.

Personal Attack: Argumentum ad hominem – attacking or praising the speaker rather than the argument itself.

Ex. “Her site-development plan will never work because she is from New Mexico.” Her birthplace has no effect on whether or not her site-development plan will work.


Argument of the People: Argumentum ad populum – imploring or siding with (or against) popular support rather than building an argument.

Ex. “Nine out of ten oil companies agree that this method is superior.” Their agreement has no effect on the quality of the method.


Appeal to Tradition: Argumentum ad traditionem – asserting that a conclusion must be true because it always has been seen as such.

Ex. “Injection wells have never presented an environmental issue in Oklahoma.” The outcomes of the future operations are separate from the operations of the past.

Component Fallacies

These fallacies are errors within reasoning itself.

Begging the Question: Petitio principia – using the conclusion itself as evidence for drawing a conclusion. This is a form of circular reasoning.

Ex. “Harmful techniques like hydraulic fracturing should be banned.” This statement assumes that hydraulic fracturing is harmful without supporting that claim.


Hasty Generalization: Dicto simpliciter – using too few observations to prove a generalization. Misleading statistics are a form of generalization.

Ex. One cow from a herd of several hundred cattle dies each week for three weeks after hydraulic fracturing operations commence, and the landowner claims all the cows will soon die. Each cow’s life is independent and three is an unrepresentative sample of the entire herd.


False Cause: Post hoc, ergo propter hoc – assuming that because an event occurs before another, that the first causes the second.

Ex. In the previous example, the landowner assumes the deaths of her cows are a result of the hydraulic fracturing operations. The timing of the operations does not prove a causal relationship with the deaths of the cows.


False Dichotomy – presenting two options as the only two possible options.

Ex. An operator argues that the landowner must lease her land now or never take advantage of the financial benefits of oil and gas production. This technique ignores the wide spectrum of other possibilities available.

Fallacies of Omission

These fallacies rely on excluding information or misleading the audience.

Stacking the Deck – ignoring examples that contradict the premise. This is a deliberate omission of facts rather than a hasty generalization based on too few facts.

Ex. “There are zero examples of hydraulic fracturing harming water supplies.” This statement presents an absolute rather than accounting for a complex and nuanced situation.


Hypothesis Contrary to Fact: Argumentum ad speculum – using an imaginary example or alternative history.

Ex. “Texas would be the leader in renewable energy if oil had not been discovered there.” Oil was discovered in Texas, and the state’s relationship with renewable energy must be argued with regard to actual history.


Check Your Knowledge

Let’s examine an example from an encounter at a wellsite. Imagine you are an oil and gas inspector visiting a well in a sensitive watershed area. You notice that a mud storage tank is not properly protected from spill runoff that could contaminate local water supplies. You approach the operator and point out the situation is not in compliance with regulation. She replies that such a regulation is unnecessary, as she has never personally been on a rig that has experienced a mud tank spill. Which fallacy is this an example of?

Answer

This is an example of the fallacy of hasty generalization. Just because this particular operator has never witnessed such a spill does not mean that it could never happen.

Images: “Showing the Strain” by Brian Smithson licensed under CC BY 2.0; “Logical-Fallacy-shutter-stock” by G. Tbov