Below is a crash course of logical fallacies (though it is a pretty complete list). I've attempted to define the fallacies in my own words so it's understandable and not just "propositional logic." I've given examples for the most common fallacies as well.
Faulty appeals make use of an outside force as an ally, but in an underhanded fashion because it fails to address the issues on evidence and fact alone.
The following are faulty appeals to ...
- Accomplishment -- a position is true because of the supporter's accomplishments.
- Authority -- insisting a position is true only on the basis of an expert's opinion.
My mechanic told me Volvos are better cars, so obviously you're wrong!
- Common Sense -- dismissing a claim simply because it lacks common sense, that is a deviation from the norm.
- Conflict -- dismissing experts in a field as wrong because the experts disagree on a specific point.
- Emotion -- an argument made to twist a person's emotions rather than present evidence.
As your politician, you should vote for me because I grew up an orphan and led a pretty miserable life in a foster home but still rose above all that!
- Experience -- using one's own experience to discount evidence because such an experience contrasts with the evidence, even if such an experience is an edge case.
Unicorns must exist, because I saw one on a hillside in Utah, just as clear as I see my computer screen!
- False Attribution -- using a false source of information as an authority.
- Fear -- using the threat of fear to sway opinion.
If you don't elect me as your congressman, this country will be plunged more deeply into recession; you'll soon be without a job and wondering what happened to the value of the dollar bill.
- Flattery -- to sway potential supporters with flattery.
- Force -- threatening punishment if such a position is not accepted.
- Hypocrisy (Tu Quoque) -- insisting a position is false because the proponent is not in line with the position.
You can't say that Dustin is wrong about orangutans--you've never even seen one!
- Ignorance -- assuming a claim is true simply because there is no evidence to make it false.
- Motive -- dismissing an idea on the basis of motive.
- Nature -- dismissing or accepting an idea based that is "unnatural" or "natural" respectively.
- Novelty -- insisting that an idea is better because it is newer.
- Pity -- to sway potential supporters on the basis of pity.
- Poverty/Wealth -- basing the validity of the conclusion on the arguers wealth.
- Probability -- saying that because something is "probable" (statistics support it as most likely) then it must be true or is overwhelmingly likely.
- Ridicule -- presenting the opponent's arguments in a ridiculous fashion to garner support.
- Spite -- to sway supporters on the basis of deep-seated spite or bitterness against the opponent.
- the Majority -- claiming an idea is true because the majority believe it.
Well, almost everyone I talked to said that Trevor would make a better class president; so, I guess you're wrong.
- the Stone -- dismissing an argument by calling it crazy without giving evidence why it should be dismissed.
You think we didn't land on the moon? That's crazy.
- Wishful Thinking -- an appeal to supporters on the basis of a wishful thought rather than an actual plan or evidence.
Faulty arguments have a logical error in the flow of thought. They may be presented with true evidence, in a meaningful and sincere manner, and even by an intelligent person, but are wrong logically and do not arrive at a valid (note: validity is different from veracity) conclusion.
- Argument to Moderation -- assuming a compromise between two positions must be correct.
- Circular Cause and Consequence -- assuming a consequence of an event is its root cause.
- Circular Reasoning -- arriving at the conclusion by assuming the conclusion.
- Homunculus Fallacy -- explaining something but inserting the same thing being explained in the explanation.
- Ignoratio Elenchi -- a valid argument that fails to address the question.
- Kettle Logic -- when multiple arguments are supplied to defend a position but the arguments are inconsistent.
- Loaded Question -- asking a question with a presupposed premise that is either false or unproven.
Have you stopped stalking girls on Facebook yet?
- Moral High Ground Fallacy -- assuming a character that one is better than someone else to win the argument.
- Moving the Goalposts -- changing the needed criterion to prove something when such evidence is provided.
- Proving Too Much -- an argument that has essentially proven something absurd. Such an argument can be easily dispelled by using Reductio Ad Absurdum.
The following are logical fallacies that have either attempted to make two things equal or equivalent that are not, or presented two things as equivalent or equal on an assumption:
- Association Fallacy -- assuming that two things that share a common property must be the same.
- Equivocation -- to redefine a term mid-argument without warning.
- Etymological Fallacy -- shifting a term's definition in one's favor based on the historical meaning.
- Fallacy of Composition -- assuming that a part of a whole has a characteristic, then the whole must also have the characteristic.
- Fallacy of Division -- assuming that since a thing has a characteristic each of its members must also have that characteristic.
- False Analogy -- an incorrectly tailored analogy.
Fracking is like taking a dentist drill and boring into the side of the tooth and then injecting drain cleaner.
- False Equivalence -- fabricating two situations as logically equivalent when they are not.
- If-by-whiskey -- usage of terms that appeal to people's emotions to support both sides of the issue without answering the question.
- Masked Man Fallacy -- incorrectly assuming that because two objects are not the same because they do not share the same attributes or properties, though they, in fact, do share such properties.
- Reification -- turning an abstract idea into a concrete one.
Smoke and Mirrors
The following is a slew of fallacies that attempt to derail the argument. All of them attempt to distract the opponent, dismiss an argument, dodge a question, or confuse the opponent. If a debate was an actual war, this would be fleeing the room or using a smoke pellet to blind the enemy.
- Ad Hominem -- appealing to an insult rather than arguing the case.
Well, your face is ugly, so there!
Dismissing an Argument
- Argument from Fallacy -- assuming that because an argument is unsound or fallacious, the conclusion must be false in reality. A conclusion can be true even if the argument is incorrect or fallacies exist.
- Chronological snobbery -- dismissing an idea because other false ideas were held at the same time.
- Continuum Fallacy -- rejecting a claim because the one objecting finds it vague.
- Fallacy of Relative Privation -- dismissing a problem because there are more important problems to solve.
- Genetic Fallacy -- dismissing an idea because of the origin of the idea.
Your argument is meaningless because it comes from a guy that was tried and found guilty of tax evasion.
- Historian's Fallacy -- assuming past historians looked at or had the same opinion on an event and had the same data to analyze the event.
- Intentional Fallacy -- insisting that the intention behind something trumps the actual manifestation of the idea.
- Nirvana Fallacy -- dismissing a solution because it is not perfect.
- Pooh-pooh -- ignoring an idea because it is deemed unworthy.
Dodging a Question
- Red Herring -- dodging a question and responding with something not pertinent to the topic.
Have you heard about squirrels?
- Shifting the Burden of Proof -- insisting on proving an argument false rather than attempting oneself to prove it true.
I think there is a small, invisible teapot that revolves around the sun and you can't prove me wrong.
- Thought-terminating cliché -- ending an argument with a saying or proverb, an attempt to "one-up" the opponent but without a real argument.
Blessed are the peacemakers for theirs is the kingdom of chocolate marshmallows.
Smokescreen to Confuse
- Misleading Vividness -- describing an exception vividly to purpose to people that such an exception is the norm.
- Proof by Verbosity -- appealing to wordy and difficult syntax to stump an opponent in understanding the argument.
You obviously are unaware of the latest tension arm in a hydravacuous internment chamber would allow for rapid heat expansible cooling to make a perpetual motion machine completely possible.
Argument From Repetition -- claiming a position is right because no one wants to discuss it further, that that person is right simply by persevering to the end of a debate.
No one else wants to argue with me? Ok, then I'm right.
Argument From Silence -- assuming a claim is true based on absence of evidence.
Proof by Assertion -- repeatedly restating the same evidence regardless of contradiction.
Six tenths of the world. Of the world. OF THE WORLD. Do you not understand that? Six tenths! That's a majority! I can keep repeating this if you don't understand it.
Shotgun Argumentation -- spewing out arguments so that the opponent cannot possibly answer all of them.
What about Bohr's Law? Or thermodynamics? How about the most recent situation in Latvia? Or the new court order that back Dr. Finwiddie's experiments? Have you also read On the Effects of Chemonuclear Radiation?
Straw Man Fallacy -- misrepresenting an opponent's position.
Proponent: I like hamburgers.
Opponent: So, you're for the massive torture, slaughter, and mishandling of cows all across the world, without any respect for them as animals. You'd rather see them be treated like cattle then treated with respect and deference.
Vacuous Truth -- an argument whose premise is not based in reality, so the conclusion is without any merit.
Some of these fallacies deal with probability, but all of them make an assumption and then twist data to suit the debater.
- Accident -- an exception is dismissed without proper grounds.
- Cherry Picking -- assuming something is true because the cases that support said position are chosen.
- Conjunction Fallacy -- assuming that an outcome that satisfies the highest number of conditions is true over one one that satisfies fewer conditions.
- False Dilemma -- presenting only two options as answers when there may well be more.
Your only options are to buy an Xbox or a Playstation for gaming. There are no other choices.
- Gambler's Fallacy -- to assume separate, independent trials have bearing on each other.
- Hasty Generalization -- making a generalization without considering all possible evidence.
- Overwhelming Exception -- making a broad, grand claim and then adding so many exceptions that such a claim is really just skeletal.
Cause and effect: the wonderful process that seems so hard to grasp, both in spelling and execution. Causes precede effects. Causes create effects. And here are the ways that these ideas are messed up:
- Fallacy of the Single Cause -- assuming there is a single cause to the situation.
- Furtive Fallacy -- insisting that such an event was caused by malevolent industries and governments in cooperation.
- Regression Fallacy -- assuming a cause when one does not necessarily exist.
- Texas Sharpshooter Fallacy -- assuming a cause to explain a group of data.
- Wrong Direction -- flipping cause and effect where the cause is the effect and the effect is the cause.
These are a little more formal and may require some study of logic to fully grasp.
- Affirming a consequent -- given a conditional (if A then B), affirming the premise because the conclusion is true.
- Affirming a disjunct -- given two options that are not exclusive, and knowing one is true, affirming the other false.
- Denying the antecedent -- given a conditional (if A then B), denying the conclusion because the premise is false.
SURGEON GENERAL WARNING: Logic and reason are the main components for smarter thinking. Be warned that such thinking can lead to analysis, thought process, reasoning, philosophy, understanding, and learning.