Cornerstones of Critical Thinking 2 Logical Fallacies and Biases

In looking at critical thinking several minimum criteria for a minimum education on several topics exist. If you don't know a good amount of very specific details about very specific ideas you will be extremely limited in successful critical thinking.

Two of the most basic topics to tackle are logical fallacies and biases. As human beings we have a nature that includes tendencies to think in and be persuaded by logical fallacies and biases that limit our ability to think rationally.

First off logical fallacies include numerous ideas that have been used in debate or presenting ideas that are faulty logic. They are sometimes accepted as valid arguments but upon good logical analysis are faulty.

If for example we look at the fallacy called ad hominem which translates to against the man it is a class of fallacies that includes personal insults. If for example in a debate someone said I think company X is poisoning our local river and we should stop them and a representative for company X responds by saying "that guy is a loser, therefore his claims have no merit, don't listen to him" that is a fallacy. An example of poor reason in creating an argument.

Regardless of any opinions regarding a person being a loser a claim by a person on a company poisoning a river could be true. It could be false too but the status of a person as a loser is irrelevant. When people use irrelevant information to dismiss claims that is a fallacy, if it is a personal insult then it's ad hominem.

For some special circumstances personal character is relevant. One example is individuals claiming that following their ideology produces morally superior individuals who are infallible or obviously superior to others and therefore validates a moral authority over others.

Such individuals with the use of claims of moral superiority invite scrutiny of their claims including alleged exemplary character. If I say I prayed myself into a state of grace in which I no longer ever commit bad acts then things like infidelity and lying on my part are entirely relevant. Relevant to those particular claims. Not to other unrelated claims.

So you really have to sort claims and relevant information supporting and refuting the claims based on what is alleged that is related. A person can have a poor claim and bad logic regarding one claim but a good argument, sound evidence and good reason regarding a different entirely separate claim.

I have previously in my blog post PISSED ! It's Not Your Fault described the following logical fallacies as common to Scientology doctrine and therefore common to the thinking of Scientologists: Personal incredulity , black and white thinking , magical thinking , the Texas sharpshooter fallacy ( aka apophenia ) , Ad Hominem , no true Scotsman ( Scientologist ) , Appeal to authority ( their own or Hubbard  ) , begging the question , genetic , burden of proof , ambiguity , bandwagon , anecdotal and of course tu quoque . Additionally fallacies like composition/division, argument to ignorance, false dichotomy, need to be well understood as well.

Several simple websites have good definitions and examples including Thou Shall Not Commit Logical Fallacies. It's a great one with two dozen of the most common fallacies well defined in simple terms. A great thing to do is to look over the list, find a fallacy or a few that you immediately understand well and can think of several examples of, find more examples, refine your ability to spot these few fallacies in others, whether in politics or philosophy or anywhere they have been used or are still used. 

After you really can see and refer to a few with extreme competence and confidence add one more at a time to take on. Challenge yourself to see what it means, why it's a poor argument to support a claim. Then find examples for that one. Then add the others until you really have at least a couple dozen under your belt. 

The real challenge is finding and calling out fallacies in your own arguments and thinking. That's the harder part. That's why you shouldn't even worry about it until it either pops up on your radar or until you know it cold in others. It's a progression like learning addition and subtraction very well is a prerequisite for learning multiplication and division.

The usual way to do it is really get basic addition and subtraction and the order of numbers down as first nature before taking the next step. That's the way to get to taking on your own fallacies and the fallacies of people you agree with.


A necessary compliment to logical fallacies in critical thinking is biases. If you take on either one without the other you are missing a lot of the picture. 

The sister page to Thou Shall Not Commit Logical Fallacies is 24 Cognitive Biases Stuffing Up Your Thinking. It lists brief definitions and examples for very common biases just as Thou Shall Not Commit Logical Fallacies takes on fallacies. 

The same tactic can be used in taking on biases with the special challenge that several biases by their nature are prejudices that cause individuals to not perceive them and often particularly perceive them if at all in other people but not themselves. That's important to understand in taking them on. If you understand they limit others but not you then you are displaying the bias being described. How can one come to believe they have a bias they don't perceive ? Look for the scientific evidence and research that asserts the bias exists at all and look for evidence it is hidden from people who hold it and evidence that everyone or people in general tend to hold the bias. This seems like a lot of work but after it's been done for a few relevant biases the time and effort declines tremendously, because the evidence that supports much of these claims is similar or the same, so you don't have to repeat the entire process every time. 

Thou Shall Not Commit Logical Fallacies has the following essential fallacies listed and defined: Strawman, slippery slope, special pleading, the gambler's fallacy, black or white, false cause, ad hominem, begging the question, appeal to authority, appeal to nature, composition/division, anecdotal, appeal to emotion, tu quoque, burden of proof, no true Scotsman, the Texas sharpshooter, the fallacy fallacy, personal incredulity, ambiguity, genetic and middle ground.

24 cognitive biases stuffing up your thinking has these biases: anchoring, confirmation bias, backfire effect, declinism, just world hypothesis, sunk cost fallacy, Dunning-Kruger effect, Barnum effect, framing effect, in-group bias, fundamental attribution error, placebo effect, halo effect, bystander effect, availability heuristic, belief bias, groupthink, optimism bias, reactance, curse of knowledge, self-serving bias, negativity bias, and spotlight effect.


This may seem like a lot but over one hundred logical fallacies have been described and an additional one hundred biases have as well.

That's far too much to take on in one shot. Just reading the definitions of all them, even with examples, won't be an effective way to learn.

You have to be humble and realize just really understanding logical fallacies or biases takes patience, repetition, time , effort and revisiting the same material periodically. 

You can find long lists of fallacies and biases and I recommend doing it after you are fairly familiar with at least a couple dozen of each and know at least a half dozen of each so well you can comfortably explain them to others and spot examples that are real and make up examples very easily.

Sometimes an obscure fallacy or bias is exactly what you need to understand the flaws in a poor argument or the problems with doing or thinking something a certain way.

Often the clue that fallacies and biases need to be checked for is something that doesn't add up, something that just feels wrong despite being presented as legitimate. 

If you want to be a good critical thinker a commitment to learning about logical fallacies and biases is an indispensable essential. 

I recently completed a long series of blog posts on something many of us encourage but rarely actually discuss - critical thinking. It's essential to good reason and in my personal opinion recovery from the harm Scientology and other cults do. Here's the entire series.

Cornerstones of Critical Thinking 1 Looking at Both Sides
http://mbnest.blogspot.com/...

Cornerstones of Critical Thinking 2 Logical Fallacies and Biases
http://mbnest.blogspot.com/...

Cornerstones of Critical Thinking 3 Paul-Elder Critical Thinking Framework
http://mbnest.blogspot.com/...

Cornerstones of Critical Thinking 4 Being A Pain In The Ass
http://mbnest.blogspot.com/...

Cornerstones of Critical Thinking 5 Show The Work
http://mbnest.blogspot.com/...

Cornerstones of Critical Thinking 6 Propaganda: 7 Most Important Techniques of Propaganda
http://mbnest.blogspot.com/...

Cornerstones of Critical Thinking 7 Rhetoric and Sublime Writing
http://mbnest.blogspot.com/...

Cornerstones of Critical Thinking 8 We Learn Together
http://mbnest.blogspot.com/...