Editing Definition (section)

==Problems==

Certain rules have traditionally been given for definitions (in particular, genus-differentia definitions).<ref>Copi 1982 pp 165–169</ref><ref name="Joyce, Ch. X">Joyce, Ch. X</ref><ref>Joseph, Ch. V</ref><ref>Macagno & Walton 2014, Ch. III</ref>
*A definition must set out the essential attributes of the thing defined.
*Definitions should avoid circularity. To define a horse as "a member of the species ''equus''" would convey no information whatsoever. For this reason, Locke adds that a definition of a term must not consist of terms which are synonymous with it. This would be a circular definition, a ''circulus in definiendo''. Note, however, that it is acceptable to define two relative terms in respect of each other. Clearly, we cannot define "antecedent" without using the term "consequent", nor conversely.
*The definition must not be too wide or too narrow. It must be applicable to everything to which the defined term applies (i.e. not miss anything out), and to nothing else (i.e. not include any things to which the defined term would not truly apply).
*The definition must not be obscure. The purpose of a definition is to explain the meaning of a term which may be obscure or difficult, by the use of terms that are commonly understood and whose meaning is clear. The violation of this rule is known by the Latin term ''obscurum per obscurius''. However, sometimes scientific and philosophical terms are difficult to define without obscurity.
*A definition should not be negative where it can be positive. We should not define "wisdom" as the absence of folly, or a healthy thing as whatever is not sick. Sometimes this is unavoidable, however. For example, it appears difficult to define blindness in positive terms rather than as "the absence of sight in a creature that is normally sighted".

===Fallacies of definition===
{{Main|Fallacies of definition}}

===Limitations of definition===
Given that a [[natural language]] such as [[English language|English]] contains, at any given time, a finite number of words, any comprehensive list of definitions must either be circular or rely upon [[primitive notion]]s. If every term of every ''definiens'' must itself be defined, "where at last should we stop?"<ref>Locke, ''Essay'', [https://books.google.com/books?id=0OoNAAAAYAAJ&dq=%22where+at+last+should+we+stop%22+inauthor:locke&pg=PA33 Bk. III, Ch. iv, 5]</ref><ref>This problem parallels the [[diallelus]], but leads to scepticism about meaning rather than knowledge.</ref> A dictionary, for instance, insofar as it is a comprehensive list of [[lexical definition]]s, must resort to [[Symbol grounding|circularity]].<ref>Generally [[Lexicography|lexicographers]] seek to avoid circularity wherever possible, but the definitions of words such as "the" and "a" use those words and are therefore circular. [http://www.m-w.com/dictionary/the] [http://www.m-w.com/dictionary/a] Lexicographer [[Sidney I. Landau]]'s essay "''Sexual Intercourse in American College Dictionaries''" provides other examples of circularity in dictionary definitions. (McKean, p. 73–77)</ref><ref>An exercise suggested by [[J. L. Austin]] involved taking up a dictionary and finding a selection of terms relating to the key concept, then looking up each of the words in the explanation of their meaning. Then, iterating this process until the list of words begins to repeat, closing in a "family circle" of words relating to the key concept.<br>(''[http://www.ditext.com/austin/plea.html A plea for excuses]'' in Philosophical Papers. Ed. [[J. O. Urmson]] and [[Geoffrey Warnock|G. J. Warnock]]. Oxford: Oxford UP, 1961. 1979.)</ref><ref>In the game of [[Vish (game)|Vish]], players compete to find circularity in a dictionary.</ref>

Many philosophers have chosen instead to leave some terms undefined. The [[Scholasticism|scholastic philosophers]] claimed that the highest genera (called the ten ''generalissima'') cannot be defined, since a higher genus cannot be assigned under which they may fall. Thus [[being]], unity and similar concepts cannot be defined.<ref name="Joyce, Ch. X"/> [[John Locke|Locke]] supposes in ''[[An Essay Concerning Human Understanding]]''<ref>Locke, ''Essay'', Bk. III, Ch. iv</ref> that the names of simple concepts do not admit of any definition. More recently [[Bertrand Russell]] sought to develop a formal language based on [[Logical atomism|logical atoms]]. Other philosophers, notably [[Ludwig Wittgenstein|Wittgenstein]], rejected the need for any undefined simples. Wittgenstein pointed out in his ''[[Philosophical Investigations]]'' that what counts as a "simple" in one circumstance might not do so in another.<ref>See especially ''[[Philosophical Investigations]]'' Part 1 §48</ref> He rejected the very idea that every explanation of the meaning of a term needed itself to be explained: "As though an explanation hung in the air unless supported by another one",<ref>He continues: "Whereas an explanation may indeed rest on another one that has been given, but none stands in need of another&nbsp;– unless ''we'' require it to prevent a misunderstanding. One might say: an explanation serves to remove or to avert a misunderstanding&nbsp;– one, that is, that would occur but for the explanation; not every one I can imagine." [[Philosophical Investigations]], Part 1 §87, italics in original</ref> claiming instead that explanation of a term is only needed to avoid misunderstanding.

Locke and [[John Stuart Mill|Mill]] also argued that [[Principle of individuation|individuals]] cannot be defined. Names are learned by connecting an idea with a sound, so that speaker and hearer have the same idea when the same word is used.<ref>This theory of meaning is one of the targets of the [[private language argument]]</ref> This is not possible when no one else is acquainted with the particular thing that has "fallen under our notice".<ref>Locke, ''Essay'', Bk. III, Ch. iii, 3</ref> Russell offered his [[theory of descriptions]] in part as a way of defining a proper name, the definition being given by a [[definite description]] that "picks out" exactly one individual. [[Saul Kripke]] pointed to difficulties with this approach, especially in relation to [[modal logic|modality]], in his book ''Naming and Necessity''.

There is a presumption in the classic example of a definition that the ''definiens'' can be stated. Wittgenstein argued that for some terms this is not the case.<ref>''Philosophical Investigations''</ref> The examples he used include ''game'', ''number'' and ''family''. In such cases, he argued, there is no fixed boundary that can be used to provide a definition. Rather, the items are grouped together because of a [[family resemblance]]. For terms such as these it is not possible and indeed not necessary to state a definition; rather, one simply comes to understand the ''use'' of the term.{{efn|One learns inductively, from [[ostensive definition]], in the same way, as in the [[Ramsey–Lewis method]].}}