Argument
Fallacy
Overview
A fallacy is the use of invalid or otherwise faulty reasoning in the construction of an argument that may appear to be well-reasoned if unnoticed. The term was introduced in the Western intellectual tradition by the Aristotelian De Sophisticis Elenchis.
Fallacies in reasoning may be invoked intentionally to manipulate or persuade by deception, unintentionally because of human limitations such as carelessness, cognitive or social biases and ignorance, or potentially due to the limitations of language and understanding of language. These delineations include not only the ignorance of the right reasoning standard but also the ignorance of relevant properties of the context. For instance, the soundness of legal arguments depends on the context in which they are made.
A fallacy does not necessarily lead to a false conclusion: it may accidentally be a result of invalid reasoning. An example is the fallacy of affirming the consequent.
Fallacies are commonly divided into "formal" and "informal". A formal fallacy is a flaw in the structure of a deductive argument that renders the argument invalid, while an informal fallacy originates in an error in reasoning other than an improper logical form. Arguments containing informal fallacies may be formally valid, but still fallacious.
A special case is a mathematical fallacy, an intentionally invalid mathematical proof with a concealed, or subtle, error. Mathematical fallacies are typically crafted and exhibited for educational purposes, usually taking the form of false proofs of obvious contradictions.
Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).
In the original texts
Passages from public-domain books where Fallacy is discussed.
Some good exemplifications of this fallacy are given by Archbishop Whately. “One case,” says he, “which may be regarded as coming under the head of Ambiguous Middle, is (what I believe logical writers mean by ‘_Fallacia Figuræ Dictionis_’) the fallacy built on the grammatical structure of…
John Stuart Mill, A System of Logic, Ratiocinative and Inductive
names the idea; states what it is; author linked in the graph; opens on it
The so-called question of presentative or representative perception, of whether an object is present to the thought that thinks it by a counterfeit image of itself, or directly and without any intervening image at all; the question of nominalism and conceptualism, of the shape in which things are present when only a general notion of them is before the mind; are comparatively easy questions when once the…
William James, The Principles of Psychology, Volume 1
states what it is; names the idea; opens on it
The discussion will be designed both (1) further to illustrate the fact that the naturalistic fallacy is a fallacy, or, in other words, that we are all aware of a certain simple quality, which (and not anything else) is what we mainly mean by the term ‘good’; and (2) to shew that not one, but many different things, possess this property. For I cannot hope to recommend the doctrine that things which are good do not…
G. E. Moore, Principia Ethica
names the idea; states what it is; opens on it
Experience is here taken as previously defined: trying to do something and having the thing perceptibly do something to one in return. The fallacy consists in supposing that we can begin with ready-made subject matter of arithmetic, or geography, or whatever, irrespective of some direct personal experience of a situation. Even the kindergarten and Montessori techniques are so anxious to get at intellectual…
John Dewey, Democracy and Education
states what it is; names the idea; opens on it
So, since the principles are the cause of our knowing and behoving we know and believe them more, because by reason of them we know also the conclusion following. Further: the man who is to have the Knowledge which comes through demonstration must not merely know and believe his principles better than he does his conclusion, but he must believe nothing more firmly than the contradictories of those principles out of…
Aristotle, The Nicomachean ethics of Aristotle
author linked in the graph; names the idea
Philosophers who discussed Fallacy
- Friedrich Nietzsche
- Theodorus the Atheist
- Robert M. Pirsig
- Dio Chrysostom
- Gaius Musonius Rufus
- Tlön, Uqbar, Orbis Tertius
- Charles Leonard Hamblin
- Hipparchia of Maroneia
- Deng Xi
- The Art of Loving
Related ideas
- Emotion
- Francis Bacon
- Argument
- Argumentation theory
- Informal logic
- Physics World
- John Stuart Mill
- Novum Organum
- Informal fallacy
- Sophistical Refutations
- Jean Buridan
- Latin
- Nyāya Sūtras
- Indian logic
- Richard Whately
- Validity (logic)
- Naturalistic fallacy
- Psychology
- Politics
- Propaganda
- Protagoras
- Rhetoric
- Socrates
- Soundness
Place in the tradition
Part of Hellenistic philosophy.