View source for Fallacies of definition

'''Fallacies of definition''' are the various ways in which [[definition]]s can fail to explain terms. The phrase is used to suggest an [[analogy]] with an [[informal fallacy]].<ref>{{Cite web|last=Kale|first=Rekhaa|date=2015-10-25|title=BLS LOGIC 1: CHAPTER 8. DEFINITION|url=http://blslogic1.blogspot.com/2015/10/chapter-8-definition.html|access-date=2020-07-21|website=BLS LOGIC 1}}</ref> Definitions may fail to have merit, because they: are overly broad, use obscure or ambiguous language, or contain circular reasoning; those are called fallacies of definition.<ref>Gibbon, Guy (2013). ''Critically Reading the Theory and Methods of Archaeology: An Introductory Guide''<!--unpaginated-->. Rowman & Littlefield. {{ISBN|9780759123427}}.</ref> Three major fallacies are: overly broad, overly narrow, and mutually exclusive definitions,<ref name="Potter">Potter, Karl H. (1991). ''Presuppositions of India's Philosophies'', p.87. Motilal Banarsidass. {{ISBN|9788120807792}}. "Under-extension", "over-extension", and "mutual exclusion".</ref> a fourth is: incomprehensible definitions,<ref>Chakraborti, Chhanda (2007). ''Logic: Informal, Symbolic and Inductive'', p.54-5. PHI Learning. {{ISBN|9788120332485}}. "Too wide", "too narrow", "incomprehensible", and "conflicting".</ref> and one of the most common<ref name="H&D"/> is circular definitions.<ref>Schipper, Edith Watson and Schuh, Edward  (1960). ''A First Course in Modern Logic'', p.24. Routledge. "Incongruous", "circular", "negative", and "obscure or figurative".</ref>

== Circularity ==
[[File:Circular definition of inflammable liquid.png|thumb|Circular definition of inflammable liquid<ref name="H&D">Hughes, Richard E. and Duhamel, Pierre Albert (1966/1967). ''Principles of rhetoric''/''Rhetoric principles and usage'', p.77/141. 2nd edition. Prentice-Hall. "Using in the definition itself the word to be defined or a close synonym of it."</ref>]]

If one concept is defined by another, and the other is defined by the first, this is known as a [[circular definition]], akin to [[begging the question|circular reasoning]]: neither offers enlightenment about what one wanted to know.<ref name="the-logical-fallacies">{{Cite web |website= Stephen's Guide to the Logical Fallacies |title= Circular Definition | url= http://onegoodmove.org/fallacy/circle.htm}} Accessed September 2, 2014.</ref> "It is a fallacy because by using a synonym in the ''definiens'' the reader is told nothing significantly new."<ref name="H&D"/>

A straightforward example would be to define ''Jew'' as "a person believing in Judaism", and ''Judaism'' as "the religion of the Jewish people", which would make ''Judaism'' "the religion of the people believing in Judaism".

== Incongruity: overly broad or narrow ==
A definition intended to describe a given set of individuals fails if its description of matching individuals is incongruous: too broad (excessively loose with parameters) or too narrow (excessively strict with parameters). For example, "a shape with four sides of equal length" is not a sufficient definition for ''square'', because squares are not the only shapes that can have four sides of equal length; [[rhombi]] do as well. Likewise, defining ''rectangle'' as "a shape with four perpendicular sides of equal length" is inappropriate because it is too narrow, as it describes only squares while excluding all other kinds of rectangles, thus being a plainly incorrect definition.

If a cow were defined as an animal with horns, this would be overly broad (including goats, for example), while if a cow were defined as a black-and-white quadruped, this would be both overly narrow (excluding: all-black, all-white, all-brown and white-brown  cows, for example)<ref name="Potter"/> and overly broad (including [[Dalmatian (dog)|Dalmatians]], for example).

== Obscurity ==
Definitions can go wrong by using [[ambiguous]], obscure, or [[figurative language]]. This can lead to circular definitions. Definitions should be defined in the most prosaic form of language to be understood, as failure to elucidate provides fallacious definitions.<ref name="the-logical-fallacies"/> Figurative language can also be misinterpreted. For example, ''golden eyes'' in a biography may lead the reader to think that the person was fictional.

An example of obscurity is [[Samuel Johnson]]'s definition for [[oat]]s: "A grain, which in [[England]] is generally given to horses, but in [[Scotland]] supports the people."<ref name=oats>{{citation|last=Johnson|first= Samuel|entry= Oats|title= A Dictionary of the English Language|year=1755|url= http://johnsonsdictionaryonline.com/?p=3471}}</ref> The thing defined (oats) should be pointed out rather than remain obscure.

==Mutual exclusivity==
The definition completely excludes what is being defined. For example, a cow might be defined as a flying animal with no legs.<ref name="Potter"/>  In reality a cow has legs and cannot fly, but this example claims to define a cow using a definition that is opposite to what a cow actually is. "Cow" and "flying animal with no legs" are mutually exclusive to each other: they cannot refer to the same thing.

== Self-contradictory requirements ==
{{expand section|date=August 2014}}
Definitions may fail by imposing conflicting requirements, making it impossible for them to apply to anything at all. For example, a cow being defined as a legless quadruped, or the term ''dynamic equilibrium'' – equilibrium state cannot be dynamic. These requirements may also be ''mutually exclusive''.{{citation needed|date=November 2022}}

== Definist fallacy ==
{{Main|Definist fallacy}}

The [[definist fallacy]] is a [[Informal fallacy|logical fallacy]], coined by [[William Frankena]] in 1939, that involves the definition of one property in terms of another.<ref name="BunninYu2008">{{citation|last1=Bunnin|first1=Nicholas|last2=Yu|first2=Jiyuan|author-link2=Jiyuan Yu|title=The Blackwell Dictionary of Western Philosophy|url=https://books.google.com/books?id=LdbxabeToQYC&pg=PA165|year=2008|publisher=John Wiley & Sons|isbn=978-0-470-99721-5|page=165}}</ref>{{clarify|reason= Does not explain anything|date=October 2017}}

== See also ==
{{Portal|Philosophy}}
* {{annotated link|Equivocation}}
* {{annotated link|Fallacy}}
* {{annotated link|Fallacy of division}}
* {{annotated link|Fallacy of equivocation}}
* {{annotated link|Fallacies of inference}}
* {{annotated link|Formal fallacy}}
* {{annotated link|Inscrutability of reference}}
* {{annotated link|Persuasive definition}}

== References ==

{{Reflist}}

{{Defining}}

{{DEFAULTSORT:Fallacies Of Definition}}
[[Category:Informal fallacies]]
[[Category:Lexicography]]