Here is a helpful catalogue of common logical fallacies that we developed for Beaner's Critical Thinking class. Being able to identify these errors in reason is critical for the loving of God with all your mind, and for commending and defending His worthiness to be loved to a rebel world.
I. FALLACIES OF DIVERSION
1) A Red Herring is the introduction of an irrelevant point into an argument. Someone may think (or want others to think) that it proves his own position or disproves his opponents, but it really doesn’t.
2) An Ad Hominem attack is attacking an opponent’s character, or his motives for holding a belief/position, instead of disproving his argument or the truth of his position.
3) Appeal to Flattery is the attempt to confuse the thoughts of the opponent with the positive feelings generated by the flatterer, thus tempering the opponent’s response in favor with the flatterer’s position.
4) The Genetic Fallacy is condemning an argument or position because of where it began, how it began, or who began it.
5) Tu Quoque is dismissing someone’s viewpoint on an issue because he himself is inconsistent in that very thing.
6) An Appeal to Faulty Authority is an appeal to someone who has no special knowledge in the area being discussed.
7) Appeal to the People is stating that a claim is true or right based on its popularity within society (quantitatively).
8) The Straw Man Fallacy is misrepresenting (by changing or exaggerating) an opponent’s position or argument in order to make it easier to refute.
9) The Sacred Cow Fallacy is when an opponent seeks to shift one’s criticism of their position or viewpoint to an unrelated noble ideal, such as liberty, religion, peace, etc., making the criticism impious, unpatriotic, etc.
10) The Root Word Fallacy ignores the fact that language changes over time. It seeks to take the ancient root meaning of a term and make unqualified application of it to the argument.
II. MAKING ASSUMPTIONS
1) Circular Reasoning (or Begging the Question) occurs when the conclusion of an argument is used in a premise of the same argument (i.e., P is true because Q is true, and Q is true because P is true).
2) An Equivocation (or the Weasel Word fallacy) changes the meaning of a particular key term in the middle of an argument.
3) Apriority is to argue from an un-argued, even subjective assumption. Presuming too much for one’s position (e.g., “Well, everybody knows that…” or “I just know…” or “I feel…” or “It seems to me that…”).
4) A Contradictory Premise is one that includes an internal inconsistency/incoherence (e.g., “Can God make a stone so big he cannot lift it?” “All truth is relative/There is no absolute truth.” “There exists an immovable object and an unstoppable force.”).
5) Poisoning the Well is the use of loaded language that attempts to damage a position or argument before it is even mentioned.
6) The Loaded Question (or Complex Question) is when an opponent actually asks two (or more) questions, but one (or more) of the questions are hidden behind the one asked.
7) The Part-to-Whole (or Fallacy of Composition) takes what is true for part of something and assumes that it must also be true for the whole of the same thing.
8) The Whole-to-Part (or Fallacy of Division) takes what is true for the whole of something and assumes that it must also be true for the parts of the same thing.
9) An Either-Or Fallacy (or False Dilemma/Dichotomy) is setting before the opponent only two alternatives, when in fact there is more than two.
10) Non Sequitur is a formal term for a “bad/invalid argument.” It means that the conclusion “does not follow” from the premises of the argument, whether or not the premises are true or false.
11) Hypothesis Contrary to Fact (or the Slippery Slope Fallacy) is to present particular, undesirable consequences as certain, when they are not. I.e., To confuse “will happen” with “might happen.”
12) The True Scotsman Fallacy is arbitrarily adding certain attributes or features to the definition of a thing or set of things that are unnecessary to its essential nature, so as to eliminate competing views.
13) The Pretended Neutrality Fallacy is the false idea that conflicting positions over ultimate questions can be settled on the “neutral” grounds of “reason” or “science” apart from any religious/philosophical pre-commitments.
14) An Anachronism is a chronological error of the representation of somebody or something out of chronological order or in the wrong historical context.
III. STATISTICAL FALLACIES
1) A Hasty Generalization is generalizing or universalizing something about a class based on a small or poor sample/example.
2) The False Analogy is to claim that some things or states of affairs which have only a few vague similarities are practically the same in every respect.
3) Post Hoc Ergo Propter Hoc (or After-This-Therefore-Because-Of-This) is concluding that since X happened before Y, then X must be the cause of Y.
4) The Appeal to Ignorance fallacy is claiming that something is true simply because nobody has yet given any evidence to the contrary in order to disprove it.
1) Appeal to Fear is when an argument’s force is built on making its opponent(s) fear the consequences of not agreeing with or doing what is desired.
2) Appeal to Pity is trying to make someone agree with or do something based on their compassion or pity toward someone else, or something associated with that person.
3) Bandwagoneering claims others should agree with or do something based on the fact that “everyone else is doing it.”
4) Special Pleading is a type of intellectual hypocrisy. It is when someone assumes one standard for himself, and another, usually more difficult to keep, for someone else in the same circumstance.
5) Repetition is repeating a message loudly and very often in the hope that it will soon be believed.
6) Transfer is the propaganda devise used to attempt to get someone to “transfer” their positive and/or negative feelings or thoughts about one thing to another unrelated thing.
7) Appeal to Snobbery is any attempt to persuade someone to believe that belief or product X would make one better, stand out from or above others. The appeal to human pride.
8) A faulty Appeal to Antiquity is to associate a belief, position or product with a long heritage, usually meaning “the older, the better.”
9) The Latest is Greatest fallacy claims that a belief, position, or product is the best simply because it is the newest.
10) Loaded Definition is presenting a definition of a key term in the debate as simple and obvious, when really it is complex and “loaded” to favor one side’s position (e.g., Faith is “believing what you know ain’t true”).
11) Sloganeering is the unwarranted use of familiar, even beloved mottos in the place of reason and evidence.
12) The Controlling Question is the phrasing of a question in order to control the response before it is made, often using: “you don’t really...surely you...don’t you?”
I call upon You, Lord, God of Abraham and God of Isaac and God of Jacob and Israel, You who are the Father of our Lord Jesus Christ, the God who, through the abundance of your mercy, was well-pleased towards us so that we may know You, who made heaven and earth, who rules over all, You who are the one and the true God, above whom there is no other God; You who, by our Lord Jesus Christ gave us the gift of the Holy Spirit, give to every one who reads this writing to know You, that You alone are God, to be strengthened in You, and to avoid every heretical and godless and impious teaching.
St Irenaeus of Lyons, Against the Heresies 3:6:4
St Irenaeus of Lyons, Against the Heresies 3:6:4