Sunday, August 22, 2010

The Logical Fallacy Repository

Below is an unofficial listing of all logical fallacies that I can presently think of. It will likely be updated from time to time. I hope that it's useful to someone out there, even though I'm not including definitions for most of these for now. If you want to know more about some of the undefined fallacies listed below, look them up on Wikipedia.

Last update: 12/11/10

Update: This list, while somewhat tentative, is most definitely of note, as it functions as a working, agile repository for all fundamental cognitive pitfalls and errors in reason. The more of the different kinds of extant mental glitches that you identify, the better that you will be at troubleshooting your peers and their belief systems.

1. My proposed fallacies/fundamental fallacies

- Qualification/categorization error - Any error where a quality is falsely attached to a concept, often in an attempt to make qualitative comparisons, or to categorize concepts. Descendant: argument from assumption (Note: argument from assumption does not necessarily have to be the result of a qualification error)

- Argument from assumption. Descendant: argument from generalization

- Argument from generalization. Descendants: induction error, deduction error

- Induction error - A particular is true, so all things sharing its quality are also true with respect to a phenomenon; an idea within a particular category possesses a given quality, so all concepts within the category also possess the quality.

- Deduction error - All things that we've observed with a quality are true with respect to a phenomenon, so a particular of these things is true despite never being demonstrated to be.

Note: Induction and deduction errors can be avoided by avoiding the process of arbitrary categorization altogether. Definitions and categories are often essential, but where multiple concepts exist, it is usually better to abstract their shared category into its constituent ideas or parts.

- Reduction/abstraction error. Descendant: false dichotomy (see below) 

- Appeal to emotion/appeal to identity - I want to believe it because it makes me feel good; I'm afraid of it being true, so I don't believe it; I believe it because it's part of who I am and I must never compromise my identity.

- Argument from personal experience

- Argument from anomaly - It's anomalous and unexplained; therefore, aliens, ghosts, etc. exist.

- Argument from unlikelihood of counter argument - What you're proposing is statistically unlikely; therefore, what I'm proposing is more statistically likely.

- Argument from finite knowledge - We don't know everything; therefore, what we think we know is probably incorrect, or may only appear depressing/scary/negative/bad because we don't have the whole picture. When we do, we'll see how amazing what we'd already been familiar with in the past really was all along.

- Logical inversion - Placing effect before cause.

- Argument from false analogy - A presented analogy is touted as representative of a scenario or concept; the analog or analogs present in the analogy are nonsensical or otherwise negative; thus, the original scenario or concept is falsely presumed nonsensical or otherwise negative.

2. Traditional fallacies accepted by the scientific and philosophic communities  

- Argument from popularity/argumentum ad populum

- Argument from faith

- Argument from ignorance - A concept must be true if you cannot disprove it, or it must be false if you cannot prove it.

- Appeal to nature/appeal to naturalism

- Appeal to authority (doubly bad when the person appealed to is, as it would turn out, not an authority on the subject after all, and is merely an authority on some subject)

- Confirmation bias/wishful thinking. Descendant: cherry-picking

- Cherry-picking. Descendant: quote mining

- Quote mining

- Cognitive dissonance - related to appeal to emotion, but is a more general display of two or more dissonant mental processes which hold opposing views as they compete for brain space

- non sequitur

- Slippery slope

- Special pleading

- Begging the question/circular reasoning

- post hoc, aka correlation/causation error - Two events are correlated in an arbitrary way; therefore, one directly caused the other.

- Moving the goal posts. Descendant: god of the gaps

- God of the gaps

- False dichotomy/dualism/binary mentality - a particular form of a reduction/abstraction error; reduction to two categories is the most common, though there are a myriad of other forms -- as many as there are numbers.

2a. Personality fallacies

- Poisoning the well

- Character assassination - related to poisoning the well, but pertaining to the overall character of a person rather than to a particular argument or point

- Guilt by association

- ad hominem

2b. Diversion fallacies

- Red herring

- Information pollution

- Strawman

With potential for future inclusion

- Appeal to empiricism/skepticism - Because we don't have evidence that it exists, it doesn't.

- Appeal to extreme skepticism - We can never know if it's true under any circumstance.

Note that this repository opens up the possibility for a hierarchy of fallacies warranting some form of decomposition.


  1. Fallacy:Noun: Something someone does in an argument that annoys me.

  2. So everything that I've said up until this point is a fallacy in your eyes, then, I take it?