Mastering Logical Fallacies
4.3 (94 ratings)
Course Ratings are calculated from individual students’ ratings and a variety of other signals, like age of rating and reliability, to ensure that they reflect course quality fairly and accurately.
735 students enrolled

Mastering Logical Fallacies

The Online Course Based on the Book, "Logically Fallacious"
4.3 (94 ratings)
Course Ratings are calculated from individual students’ ratings and a variety of other signals, like age of rating and reliability, to ensure that they reflect course quality fairly and accurately.
735 students enrolled
Created by Bo Bennett, PhD
Last updated 12/2016
English [Auto]
Current price: $20.99 Original price: $29.99 Discount: 30% off
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This course includes
  • 5 hours on-demand video
  • 1 downloadable resource
  • Full lifetime access
  • Access on mobile and TV
  • Certificate of Completion
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What you'll learn
  • notice an improvement in their reasoning and ability to make better decisions
  • recognize bad arguments more easily
  • articulate why an argument is bad
  • understand over 100 of the most common logical fallacies
  • Students are expected to have a high-school level vocabulary and reading comprehension in the English language.

This is a crash course, meant to catapult you into a world where you start to see things how they really are, not how you think they are. The focus of this course is on logical fallacies, which loosely defined, are simply errors in reasoning. 

Significantly Improve the Way You Reason and Make Decisions

  • Learn how to recognize bad arguments
  • Be able to articulate why an argument is bad
  • Learn important details on over 100 of the most common logical fallacies

Mastering Logical Fallacies

Fallacies have been around since the ancient Greek philosophers, and perhaps since the dawn of communication. Since the advent of social media, they seem to be around a lot more. Through mastering logical fallacies, you can not only correct others when they display a lapse in reasoning, but you can prevent yourself from making similar reasoning faux pas. You will be doing your part in making the world a more reasonable place.

Unlike other mentions of logical fallacies, the instructor goes into depth discussing many of the cognitive aspects of why we commit these fallacies and why we fall for them, offering academic insight in the world of logical fallacies.

Contents and Overview

This course contains 92 lectures and over 5 and a half hours of content. Each section concludes with a quiz that will help you remember what has been learned.

While this course is written for the layperson, some concepts which may be new to you but play an important role in reasoning are introduced, in section1 we will cover the basics of reasoning, arguments, beliefs, fallacies, rationality, and being a smart-ass. In sections 2–18 we will go over in detail the most common logical fallacies, the variations of those fallacies, psychological reasons behind them, examples, and exceptions. 

By the end of this course, you should be more confident in your ability to engage in rational arguments as well as present your own arguments.

Who this course is for:
  • The ideal student is one who values reason and logic, and is tired of watching people get away with bad arguments just because they sound good.
Course content
Expand all 103 lectures 05:09:13
+ Introduction to Logical Fallacies
7 lectures 28:04

While this course is written for the layperson, I do need to introduce some concepts which may be new to you but play an important role in reasoning, as well as issue a few warnings and explain how this course is organized. In this section we will cover the basics of reasoning, arguments, beliefs, fallacies, rationality, and being a smart-ass

By the end of this section, you should:

  • know the difference between reason and rationality
  • know what an argument is and the many forms it can take
  • understand how beliefs are formed
  • know what is meant by the term "fallacy"
  • know the pros and cons of being a smart-ass
  • understand that fallacious reasoning is both active and passive
Preview 00:53

Reason and rationality are not the same, and it is important to know the differences.

Preview 02:23

An "argument" is often seen as a negative experience, but this is not the type of argument we are talking about in this course.

What is an Argument?

Not all beliefs are formed the same, and not all people are biologically influenced by information in the same way.

How Beliefs are Formed

There are formal and informal fallacies. The informal fallacies are arguments in themselves where there is a degree of subjectivity.

What is a Fallacy?

Sometimes calling out fallacies is the best course of action. Sometimes it's not. Know the difference.

On Being a Smart-Ass

Sometimes an argument is fallacious. Sometimes it is the person who is making the argument who is fallacious. And sometimes it is the person interpreting the argument who is fallacious.

Fallacies: Who Commits Them?
Section 1 Quiz
10 questions
+ Ad Hominem
6 lectures 12:00

In this section we will cover the Ad Hominem fallacy in detail, including five common forms: Ad Hominem (Abusive), Ad Hominem (Circumstantial), Ad Hominem (Guilt by Association), Ad Hominem (Tu quoque), and Poisoning the Well.

By the end of this section you should be familiar with these fallacies and be able to recognize when they are committed, even if not by name.

Introduction to Section 2

Suggesting that the person who is making the argument is biased, or predisposed to take a particular stance, and therefore, the argument is necessarily invalid.

Preview 01:36

When the source is viewed negatively because of its association with another person or group who is already viewed negatively.

Ad Hominem (Guilt by Association)

Claiming the argument is flawed by pointing out that the one making the argument is not acting consistently with the claims of the argument.

Ad Hominem (Tu quoque)

Attacking the person making the argument, rather than the argument itself, when the attack on the person is completely irrelevant to the argument the person is making.

Ad Hominem (Abusive)

To commit a preemptive ad hominem attack against an opponent.  That is, to prime the audience with adverse information about the opponent from the start, in an attempt to make your claim more acceptable, or discount the credibility of your opponent’s claim.

Poisoning the Well
Section 2 Quiz
10 questions
+ Appeal to Common Belief
3 lectures 08:45

In this section we will cover the Appeal to Common Belief fallacy in detail, also known as: appeal to accepted belief, groupthink, appeal to widespread belief, appeal to the masses, appeal to belief, appeal to the majority, argument by consensus, consensus fallacy, authority of the many, bandwagon fallacy, argumentum ad numerum, appeal to the number, argumentum consensus gentium, appeal to the mob, appeal to the gallery, mob appeal, social conformance, value of community.

By the end of this section you should be familiar with this fallacy and be able to recognize when it's committed, even if not by name.

Introduction to Section 3

When the claim that most or many people in general or of a particular group accept a belief as true is presented as evidence for the claim. Accepting another person’s belief, or many people’s beliefs, without demanding evidence as to why that person accepts the belief, is lazy thinking and a dangerous way to accept information.

Appeal to Common Belief

A large group's aggregated answers to questions involving quantity estimation, general world knowledge, and spatial reasoning has generally been found to be as good as, and often better than, the answer given by any of the individuals within the group.

Wisdom of the Crowd
Section 3 Quiz
5 questions
+ Fallacies and Religion
5 lectures 21:39

In this section, we cover four fallacies that are directly related to religion: Appeal to Faith, Appeal to Heaven, Magical Thinking, and Spiritual Fallacy. It will be made clear that it is not faith, the belief in magic, Heaven, or a spiritual world that is fallacious—it is the reliance on these beliefs in place of reason in rational discourse that is fallacious.

By the end of this section, students will

  • learn when faith becomes a problem in rational discourse
  • learn why any person of any religion claiming to know the will of the gods is acting fallaciously
  • learn that magical thinking is very common, when it helps and when it doesn't
  • learn when spirituality can be a roadblock to reason
Introduction to Section 4

This is an abandonment of reason in an argument and a call to faith, usually when reason clearly leads to disproving the conclusion of an argument.  It is the assertion that one must have (the right kind of) faith in order to understand the argument.

Appeal to Faith

Asserting the conclusion must be accepted because it is the “will of God” or “the will of the gods”.  In the mind of those committing the fallacy, and those allowing to pass as a valid reason, the will of God is not only knowable, but the person making the argument knows it, and no other reason is necessary.

Appeal to Heaven

Making causal connections or correlations between two events not based on logic or evidence, but primarily based on superstition.  Magical thinking often causes one to experience irrational fear of performing certain acts or having certain thoughts because they assume a correlation with their acts and threatening calamities.

Preview 05:09

Insisting that something meant to be literal is actually “spiritual” in as an explanation or justification for something that otherwise would not fit in an explanation.

Spiritual Fallacy
Section 4 Quiz
10 questions
+ Deception Through Confusion
4 lectures 05:57

In this section we will cover the Ambiguity Fallacy, Equivocation, and the Use-Mention Error in detail. These fallacies involve playing with language and not being clear.

By the end of this section you should be familiar with these fallacies and be able to recognize when they are committed, even if not by name.

Introduction to Section 5

English is complicated and people can take advantage of that fact to confuse others.

Introduction to the Deception Fallacies

A few examples of equivocation are presented that can be seen used today.

Ambiguity Fallacy vs. Equivocation

Confusing the word used to describe a thing, with the thing itself.  To avoid this error, it is customary to put the word used to describe the thing in quotes.

Use-Mention Error
Section 5 Quiz
5 questions
+ Fallacies of Authority
6 lectures 30:09

In this section, we cover five fallacies that are directly related to authority: Anonymous Authority, Blind Authority, Just Because Fallacy, Appeal to Celebrity, and Appeal to Authority. We’ll take a detailed look at how you can know when calling on an authority is fallacious vs. rational.

By the end of this section, students will

  • learn that "they" are usually full of crap
  • learn how dangerous blindly following authority can be
  • learn how celebrities persuade us even though they shouldn't
  • learn when believing an authority is a helpful heuristic, and when it is not
  • learn that rational thinkers don't say "just because"
Introduction to Section 6

Using an authority as evidence in your argument when the authority is not really an authority on the facts relevant to the argument.  As the audience, allowing an irrelevant authority to add credibility to the claim being made.

Appeal to Authority

Accepting a claim of a celebrity based on his or her celebrity status, not on the strength of the argument.

Appeal to Celebrity

When an unspecified source is used as evidence for the claim.  This is commonly indicated by phrases such as “They say that...”, “It has been said...”, “I heard that...”, “Studies show...”, or generalized groups such as, “scientists say...”  When we fail to specify a source of the authority, we can’t verify the source, thus the credibility of the argument.  Appeals to anonymous sources are more often than not, either a way to fabricate, exaggerate, or misrepresent “facts” in order to deceive others into accepting your claim.  At times, this deception is done subconsciously -- it might not always be deliberate.

Anonymous Authority

Asserting that a proposition is true solely on the authority making the claim while extreme cases also ignore any counter evidence no matter how strong.  The authority could be parents, a coach, a boss, a military leader, or a divine authority.

Blind Authority

Refusing to respond to give reasons or evidence for a claim by stating yourself as the ultimate authority in the matter.  This is usually indicated by the phrases, “just trust me”, “because I said so”, “you’ll see”, or “just because”.  The just because fallacy is not conducive to the goal of argumentation -- that is coming to a mutually agreeable solution.  Nor is it helpful in helping the other person understand why you are firm on your position. “Just because” is not a reason that speaks to the question itself; it is simply a deflection to authority (legitimate or not).

Just Because Fallacy
Section 6 Quiz
10 questions
+ Fallacies of Emotion
6 lectures 17:36

In this section, we cover six fallacies that are directly related to emotion: Appeal to Ridicule, Appeal to Pity, Appeal to Fear, Appeal to Emotion, Appeal to Desperation, and Appeal to Anger. We are both creatures of emotion and logic, and despite what some may want to believe, emotion is a very important part of our humanity. Reason alone cannot guide our actions, but emotions often get in the way. In this section we will discuss this important distinction.

By the end of this section, students will learn

  • how pity should not guide reason
  • emotion can be both a powerful ally and foe to reason
  • desperate times may call for desperate measures, but not irrational ones
  • how talking louder and with more anger does not make one more right
  • how powerful fear can be in clouding our ability to reason
Introduction to Section 7

This is the general category of many fallacies that use emotion in place of reason in order to attempt to win the argument.  It is a type of manipulation used in place of valid logic.

Appeal to Emotion

Arguing that your conclusion, solution, or proposition is right based on the fact that something must be done, and your solution is "something."

Appeal to Desperation

When fear, not based on evidence or reason, is being used as the primary motivator to get others to accept an idea, proposition, or conclusion.

Appeal to Fear

When the emotions of anger, hatred, or rage are substituted for evidence in an argument.

Appeal to Anger

The attempt to distract from the truth of the conclusion by the use of pity.

Appeal to Ridicule / Pity
Section 7 Quiz
10 questions
+ Argument From Ignorance
5 lectures 12:00

In this section we will cover the Argument From Ignorance fallacy in detail, also known as: appeal to ignorance, absence of evidence, argument from personal astonishment [form of], argument from Incredulity [form of].

By the end of this section you should be familiar with this fallacy and be able to recognize when it is committed, even if not by name. You will have practice identifying this fallacy in real world contexts.

We will also answer the big question, is absence of evidence, evidence of absence?

Introduction to Section 8

The assumption of a conclusion or fact based primarily on lack of evidence to the contrary.  Usually best described by, “absence of evidence is not evidence of absence.”

Absence of Evidence

There is an infinity of things we cannot prove -- the moon being filled with spare ribs is one of them.  Now you might expect that any “reasonable” person would know that the moon can’t be filled with spare ribs, but you would be expecting too much.  People make wild claims, and get away with them, simply on the fact that the converse cannot otherwise be proven.

Proof vs. Evidence

Plausibility is essentially believably, and people believe things for all sorts of reasons, many of which are not rational.

Probability vs. Plausibility
Not all people are equal in terms of dispositions to fallacies, and this one is no exception.
Dispositions to This Fallacy
Section 8 Quiz
5 questions
+ Circular Reasoning and the Fallacious Question
4 lectures 10:13

In this section, we cover three fallacies that are related: Begging the Question, Circular Reasoning, and Complex Question Fallacy. Circularity is common, sometimes humorous, and some would argue it is also necessary. But it doesn't have to be fallacious.

By the end of this section, students will learn

  • when circularity is fallacious and when it is not
  • how to counter the "all reasoning is circular" argument
  • how to identify the complex question
  • why the loaded question tricks us
  • the difference between begging the question and raising the question
Introduction to Section 9

A type of reasoning in which the proposition is supported by the premises, which is supported by the proposition, creating a circle in reasoning where no useful information is being shared.  This fallacy is often quite humorous.

Circular Reasoning

Any form of argument where the conclusion is assumed in one of the premises.  Many people use the phrase “begging the question” incorrectly when they use it to mean, “prompts one to ask the question”.  That is NOT the correct usage. Begging the question is a form of circular reasoning.

Begging the Question

A question that has a presupposition built in, which implies something but protects the one asking the question from accusations of false claims.  It is a form of misleading discourse, and it is a fallacy when the audience does not detect the assumed information implicit in the question, and accepts it as a fact.

Complex Question Fallacy
Section 9 Quiz
5 questions
+ Fallacies of Poor Statistical Thinking
8 lectures 25:26

In this section, we cover seven fallacies that are related by the use and abuse of statistics: Multiple Comparisons Fallacy, Lying with Statistics, Ludic Fallacy, Hasty Generalization, Fake Precision, Biased Sample Fallacy, and Base Rate Fallacy. 

By the end of this section, students will learn

  • how important it is to pay attention to a study's sampling method and size
  • what statistical significance is
  • how easily we are deceived by charts, graphs, and figures
  • when common sense should trump statistics
  • how exact numbers are deceiving
  • that when something works "sometimes," it is often the equivalent of not working at all, due to probability alone
Introduction to Section 10

In inductive arguments, there is always a chance that the conclusion might be false, despite the truth of the premises.  This is often referred to as “confidence level”.  In any given study or poll, there is a confidence level of less than 100%.  If a confidence level is 95%, then one out of 20 similar studies will have a false conclusion.  If you make multiple comparisons, say 20 or more where there is a 95% confidence level, you are likely to get a false comparison.  This becomes a fallacy when that false comparison is seen as significant rather than a statistical probability.

Multiple Comparisons Fallacy

Numbers don't lie, but them people who use them do.

Lying with Statistics

Assuming flawless statistical models apply to situations where they actually don’t.  This can result in the over-confidence in probability theory or simply not knowing exactly where it applies as opposed to chaotic situations or situations with external influences too subtle or numerous to predict.

Ludic Fallacy

Drawing a conclusion based on a small sample size, rather than looking at statistics that are much more in line with the typical or average situation.

Hasty Generalization

Using implausibly precise statistics to give the appearance of truth and certainty, or using negligible difference in data to draw incorrect inferences.

Fake Precision

Drawing a conclusion about a population based on a sample that is biased, or chosen in order to make it appear the population on average is different than it actually is.

Biased Sample Fallacy
Ignoring statistical information in favor of using irrelevant information, that one incorrectly believes to be relevant, to make a judgment.  This usually stems from the irrational belief that statistics don’t apply in a situation, for one reason or another when, in fact, they do.

Base Rate Fallacy
Section 10 Quiz
10 questions