Rules for Definitions
Neither Too Broad or Too Narrow

The point of a definition is to identify the referents of a concept. A definition that does not pick out the right referents- -one that includes too much or too little--is not doing its job.

A definition is too broad if it includes things that are not referents of the concept.


Humans are two-legged animals.

This definition is too broad because the defining phrase "two-legged animal" includes birds as well as humans.

A definition is too narrow if it fails to include things that are referents of the concept.


Humans are religious animals

This definition is too narrow because, no matter how widespread religious belief may be, some people are atheists.

A Genus and a Differentia | Neither Too Broad Nor Too Narrow |
Essential Attributes | Avoid Circularity | Avoid Negative Terms | Avoid Vagueness

Rules for Definitions

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