In this lesson, we will examine logical fallacies which are misconceptions resulting from flawed reasoning.  Learning how to spot and identify fallacies is an important part of critical thinking.

Learning Objectives

After completing this module you will be able to identify logical fallacies and demonstrate knowledge with a minimum quiz score of 70%.


Graphic with Logical Fallacies
by Rochelle Brooks


There are two types of logical fallacies.  Formal Fallacies are problems with how you say things.  It is ideas that are in the wrong order, or the wrong form, which makes nonsense of the argument.  The other type, Informal Fallacies are errors in the content of what you are saying.  We will examine both types of fallacies.

  1. Strawman Argument is one I see a lot in political debates and conversations.  It involves attaching someone for a position they don’t actually hold. Instead of dealing with the person’s actual arguments, you argue against an easy to defeat position that they don’t have.  Deliberately mischaracterizing someone’s opponent’s position to deceive people is unethical.
  2. Appeal to Ignorance is most often used to promote multiple contradictory conclusions at the same time.  Appeal to ignorance uses the fact that something is unknown as evidence.  For example, since no one has proven that there is life on other planets, there must not be life on other planets.  You could also use the same argument to support the opposite since no one has proven there isn’t life on other planets, there must be life on other problems.
  3. Ad Hominem is when you attack the person instead of using sound reasoning.  It’s when you reject or criticize another person’s view based on their personal characteristics, background, appearance, or other personal factors.  Verbally attacking someone doesn’t prove an argument true or false. In politics, this is referred to as mudslinging.
  4. False Dilemma/False Dichotomy reasoning limits options to two when there are actually other options or presenting the options as mutually exclusive.  This fallacy oversimplifies the range of options.  It is not a fallacy if there actually are only two options.  It is a manipulation designed to polarize, making a hero of one side and demonizing the other.  It’s commonly used in politics as a way of forcing the public to support unpopular legislation or policies.
  5. Slippery Slope moves from a seemingly benign premise and working through a number of steps to an improbable extreme.  It suggests unlikely outcomes when there isn’t enough evidence to think so.
  6. Bandwagon assumes something is true or correct because other people agree.
  7. Circular Argument is taking what you assumed beforehand and repeating it without arriving at any new conclusions.  A claim that uses its own conclusion as its premise.
  8. Equivocation or ambiguity is the deliberate use of a word or phrase to confuse, deceive or mislead by sounding like you are saying something else.  A single word can say two different things.  In comedy, it is called a play on words but in a political conversation, it becomes a fallacy.
  9. Appeal to Pity for compassion is a fallacy of relevance.  Personal attacks and emotional appeals are not relevant to whether something is true.  These appeals often appear as emotional manipulation.  Truth and falsity are not emotional categories, they are factual.  This fallacy occurs when we confuse feelings for facts.
  10. Appeal to Authority occurs when authority is misused.  We can cite relevant authorities, leaving out other testable and concrete evidence, as if expert opinion is always correct.  It also includes citing irrelevant, poor, or false authorities.  This can be tough to identify because it is normally good and responsible to cite relevant authorities.    Even authorities can be wrong sometimes.  At one point scientific experts thought the world was flat.  Authorities should be treated with a degree of skepticism.
  11. Hasty Generalization is a statement that lacks sufficient evidence to support it.  While these statements are generally true, they are not always true.  This may be the most common logical fallacy because there is no agreement as to what constitutes sufficient evidence.  The amount of evidence needed can vary with the claim.  Adding a qualifier like sometimes, maybe, or often prevents hasty generalizations.
  12. Red Herring is a distraction from the topic using some sentiment that seems to be relevant but is not really on topic.  They are typically related to the topic but are not relevant enough to be helpful.  They don’t provide clarity, instead, they confuse and distract.  We can prevent this fallacy by clarifying how our part of the discussion is relevant to the core topic.
  13. Tu Quoque is also referred to as appealing to hypocrisy.  It distracts from the topic by pointing out the hypocrisy in others.  It neither addresses the issue nor proves a point because even hypocrites can tell the truth it is simply a diversionary tactic.  It deflects criticism away from one person by accusing the other person of the same or a comparable problem. This is an attempt to divert blame, but it only distracts from the initial issue.  Simply pointing out hypocrisy is not a fallacy when it is true, it becomes a fallacy when used to neutralize criticism and distracts from the issue.
  14. Casual is a logical breakdown when identifying a cause.  There are many forms of causal fallacies.  One is that because one thing occurs after another it is caused by the first thing.  Another is thinking that two things found together are causally related.  Correlation is not evidence of causation.
  15. Sunk Costs is being so invested in a project that there is a reluctance to abandon it, even when it’s proven futile.  In economics sunk costs are expenses that can not be recovered.  This can happen because people want a sense of accomplishment or they are overly comfortable with an unwieldy project.


There are other logical fallacies and some information falls into more than one category.  Logical Fallacies can be either illegitimate arguments or irrelevant points.  They can often be identified because they lack evidence that supports their claim. Look for these common fallacies when determining the value of information.


Created on

Lesson 2 Quiz

1 / 6

"The Quran is true; it says so in the Quran, so it is true."  What type of fallacy is this?

2 / 6

"Although my husband and I argue constantly and he cheats on me, but we have been together 25 years, so I might as well stay with him."  What type of fallacy is this?

3 / 6

"So, I told a little white lie, you lie also Mark."   What type of fallacy is this?

4 / 6

"All Jewish people observe the Sabbath."   What type of fallacy is this?

5 / 6

The parent of a teenager will not buy them a sewing machine.  The teenager says, "But if you don't buy me a sewing machine I'll never learn to sew.  I won't be able to become a dress designer.  I'll never be able to support myself."  What type of fallacy is this?

6 / 6

"Every time it hails I get a flat tire.  Something in the hail must flatten my tires".  What type of fallacy is this?

Your score is

The average score is 77%




Cook, K., (2018, July 26).  15 Common Logical Fallacies and How to Spot Them.  Retrieved April 5, 2021, from https://blog.hubspot.com/marketing/common-logical-fallacies

Carroll, L., & Heick, C. (2020, October 25). 8 science-based strategies for Critical Thinking: Critical Thinking. Retrieved March 21, 2021, from https://www.teachthought.com/critical-thinking/8-science-based-strategies-for-critical-thinking/

Tykoski, M. (2016, June 23). The scientific method: Critical thinking at its best. Retrieved March 21, 2021, from https://www.gcu.edu/blog/teaching-school-administration/scientific-method- critical-thinking-its-best