Logical Fallacies

We are slowly going through the main logical fallacies, with examples and also with how to refute them. You can use this in all aspects of your life, whether it be science vs. pseudo-science, religion vs. atheism or agnosticism, the daily assault of advertising and consumerism, or simply to put your own belief systems to the test.

This page will have an introduction to each one. Click the title of the fallacy to read the full article.

First, some definitions from the Introduction.
Logical: Reasoning or capable of reasoning in a clear and consistent manner. Reasonable.
Fallacy: A deceptive, misleading or false notion or belief. A misleading or unsound argument.

Another thing that is really important as we get started is to keep in mind the difference between Fact versus Opinion, and the difference between Objective versus Subjective.
Fact: something that actually exists; reality; truth. Something known to exist or to have happened. Something known to be true.
Opinion: a personal view, attitude, or appraisal.

Pointing out that an issue is actually not based on fact, but rather an opinion, can end an argument that can never be solved. If I say that I make the best cookies in the world, that isn’t based on fact, simply my own opinion.
Objective: not influenced by personal feelings, interpretations, or prejudice; based on facts; unbiased. Of or pertaining to something that can be known, or to something that is an object or a part of an object; existing independent of thought or an observer as part of reality.
Subjective: existing in the mind; belonging to the thinking subject rather than to the object of thought (opposed to Objective)

The Fine Art of Baloney Detection

Information from Carl Sagan and Michael Shermer about how to detect baloney with skeptical thinking.

Click the titles of the fallacies below to read the full article, which includes examples and ideas on how to refute them.
1. Straw Man

Our first Logical Fallacy is the Straw Man Argument. This is a great one to start with on our journey because it’s quite common and easy to spot.

A straw man: a dummy stuffed with straw. It’s too weak to fight back.

Arguing against a position specifically created to be easy to argue against, rather than the position held by someone who opposes that point of view.

So, when you state your position, your opponent replies not to what you said, but to a distorted and exaggerated caricature of what you said, that is obviously harder to defend.

2. Ad Hominem (A Personal Attack)

This logical fallacy is also very common, in my experience. It’s called Ad Hominem, which is roughly translated from the Latin for “to the person.” It’s a personal attack against you instead of your argument. It can be subtle because it isn’t just that they call you a bad name, but they use a weakness or characteristic of you to imply that your argument is weak.

3. Tu Quoque (You Too)

Tu quoque is Latin for “You too”. So you justify your wrong action because someone else also does it. “My evidence may be invalid, but so is yours.”

4. Argumentum Ad Ignorantiam (Argument from Ignorance)

Argumentum Ad ignorantiam means the Argument from Ignorance. It basically states that a specific belief is true because we don’t know that it isn’t true. This logical fallacy can also be called the Negative Proof Argument, or Appeal to Ignorance.

With a great video by Neil deGrasse Tyson.

5. Argument From Authority (Appeal to Authority)

Stating a claim is true because a person or group of perceived authority says it’s true. The claimant emphasizes the many years of experience and/or formal degrees held by the person or organization making the claim.

This argument is the opposite of the Ad Hominem Argument because the arguer appeals to positive characteristics of the source to support their argument, such as its perceived authority. If an advertisement shows someone wearing a white labcoat or a stern business suit, that is an appeal to authority.

6. Argumentum Verbosium (Proof by Intimidation or Proof by Verbosity)

The argument is so complex, so long-winded and so poorly presented that you are obliged to accept it, simply to avoid being forced to sift through its minute details.

"If you can't dazzle them with your brilliance, baffle them with your bullshit." This is common with scammers with pseudo-scientific products they are trying to sell. Conspiracy theorists can also fall back on this logical fallacy.

7. The Red Herring

The red herring is a pungent fish that is dragged across the path of a fox in a fox hunt to divert the hounds. So in an argument a Red Herring is used to divert you. The opponent responds with a different argument that does not address the original issue. Sometimes this is done in ignorance, but often it's deliberate. There is usually an appeal to emotion in the diversion. There are many sub-types of this fallacy.~

8. Cherry-Picking
Cherry-Picking is when you count the hits and ignore the misses. It is used when only certain quotes, data, studies or research are used to support an argument while ignoring other valid and credible quotes, data, studies and research.

9. Moving the Goalpost (Raising the Bar)

A common informal logical fallacy in which the arguer, when presented with evidence against one of his claims, redefines his claim without acknowledging the validity of the evidence and counterargument. In other words, the arguer doesn’t like what he hears so he simply changes what would satisfy the argument. In doing so, it can make any claim at all vacuously true and invulnerable to reasoned disproof.

10. Slippery Slope (Fallacy of the Beard)

This fallacy wrongly assumes that one thing must lead to another, and another and before you know it you get to something awful. Therefore you can’t do the first thing. This is a very common fallacy. It’s also known as the Fallacy of the Beard. In an argument, it is the situation where acceptance of a minor detail of the opposing position will greatly weaken your position.

11. God of the Gaps in Science and Faith

“I can’t understand this so God did it.” An argument from ignorance. Includes a great video of Neil deGrasse Tyson explaining the God of the Gaps through scientific history.

12. The Availability Heuristic (The Anecdotal Fallacy)

Determining probability by the ease with which relevant examples come to mind, or by the first thing that comes to mind.

13. Non Sequitur (Does Not Follow)

Non Sequitur means “does not follow” in Latin. When the conclusion does not necessarily follow from the premises, you’ve committed this logical fallacy. A logical connection is implied where none exists.

14. Special Pleading (Double Standard)

Special Pleading is a fallacy where you support your argument with arbitrary exceptions that apply only to you or a group that you have a special interest in. Basically it’s creating a Double Standard. This fallacy can be hard to recognize.

15. The Bandwagon Fallacy (Appeal to Popularity or Argumentum ad Populum)

The Bandwagon Fallacy goes by several names. Two other common ones are Appeal to Popularity and Argumentum ad Populum.

Basically, if X is popular it must be good or correct (or if X is unpopular, it's wrong).