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The term quantifier variance refers to claims there is no uniquely best ontological language with which to describe the world.〔 According to Hirsch, it is an outgrowth of ''Urmson's dictum'': The term "quantifier variance" rests upon the philosophical term 'quantifier', more precisely existential quantifier. A 'quantifier' is an expression like "there exists at least one ‘such-and-such’".〔 ==Quantifiers== The word ''quantifier'' in the introduction refers to a variable used in a domain of discourse, a collection of objects under discussion. In daily life, the domain of discourse could be 'apples', or 'persons', or even everything.〔 In a more technical arena, the domain of discourse could be 'integers', say. The quantifier variable ''x'', say, in the given domain of discourse can take on the 'value' or designate any object in the domain. The presence of a particular object, say a 'unicorn' is expressed in the manner of symbolic logic as: ::∃ ''x''; ''x'' is a unicorn. Here the 'turned ''E'' ' or ∃ is read as "there exists..." and is called the symbol for existential quantification. Relations between objects also can be expressed using quantifiers. For example, in the domain of integers (denoting the quantifier by ''n'', a customary choice for an integer) we can indirectly identify '5' by its relation with the number '25': ::∃ ''n''; ''n'' × ''n'' = 25. If we want to point out specifically that the domain of integers is meant, we could write: ::∃ ''n'' ∈ ℤ; ''n'' × ''n'' = 25. Here, ∈ = ''is a member of...'' and ∈ is called the symbol for set membership; and ℤ denotes the set of integers. There are a variety of expressions that serve the same purpose in various ontologies, and they are accordingly all quantifier expressions.〔 Quantifier ''variance'' is then one argument concerning exactly what expressions can be construed as quantifiers, and just which arguments of a quantifier, that is, which substitutions for ‘such-and-such’, are permissible.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Quantifier variance」の詳細全文を読む スポンサード リンク
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