Skip to main content
Social Sci LibreTexts

8.1.5: Types of Fallacies

  • Page ID
    113678
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)

    Bad Reasons Fallacy (Argumentum ad Logicam)

    In this fallacy, the conclusion is assumed to be bad because the arguments are bad. In practice, a premise of the argument is bad and therefore the conclusion is bad or invalid. This fallacy is seen often in debate or argumentation. We summarize the fallacy as: He gave bad reasons for his argument; therefore, his argument is bad. Consider the following claim:

    The new employee is too quiet and has no sense of style. We should fire him.

    The problem here should be obvious. To be a good employee does not require a certain look or the ability to put together interesting outfits. (Just look around your campus or workplace and you’ll probably see how true this is.) As such, the reasons for concluding the new faculty member should be fired are bad. We commit a fallacy if the conclusion to fire him is also bad or wrong. While the given reasons don’t necessarily support the conclusion, there may be others that do.

    Fallacy of Quantitative Logic

    Fallacies of quantitative logic revolve around the grammatical structure of the proposition. The focus is on the use of some sort of quantifying word such as “all” or “some.” Consider this example:

    All philosophers are wise.

    We can show the flaw in this statement by simply finding a counter-example. And since the fact of being wise is abstract, how do we truly know if one is wise or not? Consider how the statement changes with the use of a different quantifier:

    Some philosophers are wise.

    This statement is stronger because it allows for the possibility there are counter- examples. However, the error arises from the fact that it is not a known quantity. We must infer from the statement that some philosophers are not wise.

    Let’s look at another example:

    All conservatives are Republicans. Therefore, all Republicans are conservatives.

    OR

    All liberals are Democrats. Therefore, all Democrats are liberal.

    Without thinking too hard you can probably think of one counter-example.

    Hasty Generalization Fallacy

    A hasty generalization fallacy occurs when reaching a conclusion without any, or little, evidence to back up the argument. I recently celebrated an event at a local restaurant that is known for its exceptional food. That night I got a severe case of food poisoning. If I told all of my friends not to eat at that restaurant because they would get food poisoning, I am guilty of a hasty generalization.

    Ad Hominem Fallacy

    The ad hominem fallacy occurs when we shift our focus from the premises and conclusions of the argument and focus instead on the individual making the argument. An easy way to remember this fallacy is to think of it as the personal attack fallacy. This type of fallacy is often used in political campaigns where candidates focus on the personal aspects of a candidate rather than his or her qualifications.

    It is the weak form of arguing that many of us employed on our elementary school playgrounds such as this exchange:

    Bill: I think we should go back to class now.

    Jane: I don’t think we need to worry about it.

    Bill: Well, the bell rang a few minutes ago. We’re going to be late.

    Jane: Well, you’re a big jerk and don’t know anything, so we don’t have to go back to class.

    If we examine this exchange we can see that Bill’s arguments are sound and supported by what appears to be good evidence. However, Jane ignores these and focuses on Bill’s supposed character – he’s a big jerk. The fallacy happens when we connect the truth of a proposition to the person asserting it.

    Appeal to Authority Fallacy

    When we appeal to authority we claim the truth of a proposition is guaranteed because of the opinion of a famous person. Appeals to authority look like this:

    Authority figure X says Y. Therefore, Y is true.

    We see this fallacy in play regularly in commercials or other advertisements featuring a doctor, lawyer, or other professional. Think about, for example, ads for the latest weight loss supplement. A doctor will discuss the science of the supplement. At times she will mention that she used the supplement and successfully lost weight. Even though we do learn something about the specifics of the supplement, the focus is on the doctor and her implied authoritative knowledge. We are to infer that the supplement will work because the doctor says it will work.

    The fallacy in this type of reasoning occurs when we confuse the truth of the proposition with the person stating it. Instead of considering the strength of the argument and any evidence associated with it, we focus solely on the individual.

    Begging the Question Fallacy

    A begging the question fallacy is a form of circular reasoning that occurs when the conclusion of the argument is used as one of the premises of the argument. Arguments composed in this way will only be considered sound or strong by those who already accept their conclusion.

    Dilbert: And we know mass creates gravity because more dense planets have more gravity.

    Dogbert: How do we know which planets are more dense?

    Dilbert: They have more gravity.

    To see how begging the question develops as a fallacy, let’s turn to standard arguments in the abortion debate. One of the common arguments made by those who oppose legalized abortion is the following:

    Murder is morally wrong. Abortion is murder. Therefore, abortion is morally wrong.

    Most people would agree with the first premise that murder is morally wrong. The problem, then rests in the second premise. Not all individuals would agree that abortion is murder. However, as presented, the premise creates a presumption it is valid in all cases.

    Those who advocate for legalized abortion are not immune from this fallacy. One of their standard arguments is:

    The Constitution guarantees Americans the right to control their bodies. Abortion is a choice affecting women’s bodies. Therefore, abortion is a constitutional right.

    Like the previous example, the second premise generates a potential stopping point. While the choice to have or not have an abortion does clearly impact a woman’s body, many individuals would argue this impact is not a deciding issue.

    Either-Or Fallacy

    The thrust of the fallacy occurs when we are only given the choice between two possible alternatives, when in fact more than two exist. It may be looked at as a false dilemma.

    Returning to the abortion debates, we can see a form of this fallacy in play by simply looking at the way each side refers to itself. Those who oppose legalized abortion are Pro-Life. The implication here is that if you are for abortion then you are against life. The fallacy in this case is easy to figure out – there are many facets of life, not just abortion. Those who favor legalized abortion are Pro-Choice. The implication here is that if you are against abortion, then you are against choices. Again, the reasoning is faulty.

    There is no black-and-white situation. It’s all part of life. Highs, lows, middles.

    ~ Van Morrison

    False Cause Fallacy

    Sometimes called a Questionable Cause fallacy, this occurs when there exists a flawed causal connection between events. The fallacy is not just a bad inference about connection between cause and effect, but one that violates the cannons of reasoning about causation. We see two primary types of this fallacy.

    Accidental or coincidental connection occurs when we assume a connection where one might or might not exist. We say event C caused event E when we have no clear proof. Here’s an example:

    Yesterday Jen went out in the rain and got soaked. The next day she was in bed with the flu. Therefore, the rain caused her to get sick.

    Most of us probably grew up hearing statements like this without ever realizing we were being exposed to a logical fallacy in action. Flu is caused by exposure to a virus, not to bad weather.

    The other type of causal fallacy occurs with a general causation between types of events. For example, we know that drinking excessive amounts of alcohol leads to alcoholism and cirrhosis of the liver. However, not every individual who drinks excessively develops either of these diseases. In other words, there is a possibility that the disease will occur as a result of excessive drinking, but it is not an absolute.

    Red Herring Fallacy

    This fallacy occurs when we introduce an irrelevant issue into the argument. The phrase “red herring” comes from the supposed fox hunting practice of dragging a dried smoke herring across the trail so as to throw off the hound from the scent. In logical reasoning, the red herring fallacy works in much the same way. No, this doesn’t mean you make the argument while smelling like an old fish. What it does mean is that we attempt to distract the audience by introducing some irrelevant point, such as this:

    Each year thousands of people die in car accidents across the country. Why should we worry about endangered animals?

    This argument is trying to get us to focus on dead people instead of animals. While car accidents and the deaths resulting from them are a serious issue, this fact does not lessen the importance of worrying about endangered animals. The two issues are not equated with each other.

    Slippery Slope Fallacy

    This fallacy occurs when we assume one action will initiate a chain of events culminating in an undesirable event later. It makes it seem like the final event, the bottom of the slope, is an inevitability. Arguments falling prey to the slippery slope fallacy ignore the fact there are probably a number of other things that can happen between the initial event and the bottom of the slope. We hear examples of the slippery slope fallacy all around us:

    If we teach sex education in school, then students will have more sex. If students have more sex, we will have a rash of unplanned pregnancies and sexually transmitted diseases. Students will be forced to drop out of school and will never have the chance to succeed in life.

    Clearly, just learning about sex doesn’t automatically mean that you will engage in sex. Even more unlikely is the fact that merely learning about sex will force you to drop out of school.

    Strawman Fallacy

    This fallacy occurs when a speaker appears to refute the argument that is presented, but in reality the speaker refutes an argument that was not brought up. The best strawman arguments will argue the new point to a conclusion that appears solid; however, because their point is not the original point, it is still a fallacy.

    Examples of the strawman fallacy are everywhere and can appear to be quite persuasive:

    President Obama cannot truly have American interests in mind because he’s not truly American but Muslim.

    Statements similar to this were quite prevalent during the 2008 Presidential election and still appear on occasion. The assumption here is that if a person follows Islam and identifies as Muslim they clearly can’t be American or interested in America. While there are many potential flaws in this argument as presented, for our purpose the most obvious is that there are many Americans who are Muslim and who are quite interested and concerned about America.

    False Analogy Fallacy

    When we use analogies in our reasoning, we are comparing things. A fallacy of weak analogy occurs when there exists a poor connection between examples. Structurally, the fallacy looks like this:

    A and B are similar.

    A has characteristic X. Therefore, B has characteristic X.

    This fallacy often occurs when we try to compare two things that on the surface appear similar. For example:

    Humans and animals are both living, breathing beings. Humans have civil rights. Therefore, animals have civil rights.

    The problem in this argument is that while humans and animals are alike in their living and breathing status, there are numerous other ways they differ. We commit a fallacy when we infer that based on this initial similarity, they are similar in all other ways as well.

    Non-Sequitur

    There are times when a conclusion does not follow from a statement. In this fallacy, an argument where the conclusion may be true or false, but there exists a disconnect within the argument itself. Some of these are so blatant we are left wondering how someone got to the conclusion they did. An example of this may be if I walk around my campus and say that we should not build our new multi-level parking structure because the elevators are not well cleaned inside of the campus. Clearly, my conclusion does not align with my argument.

    Bandwagon Fallacy

    If you have ever seen someone take action, or believe in something simply because everyone else did, you may have witnessed the Bandwagon Fallacy. During the most recent presidential election, social media sites showed an increase in hate speech and vitriolic language. Many people actually told “friends” they would delete them if they had voted for Trump. There was a wave of actions like this across the country. Did people truly want to unfriend everyone that they knew voted for Trump, or did they jump on the bandwagon?

    Contributors and Attributions


    8.1.5: Types of Fallacies is shared under a CC BY-NC license and was authored, remixed, and/or curated by LibreTexts.

    • Was this article helpful?