SUBJECT: Philosophy

8. Definition by Genus and Difference
An intensional (connotative) definition assigns meaning to a word by indicating the qualities or properties that the word connotes. A definition by genus and difference is a type of intensional definition that assigns meaning to a word by defining it as a subclass of a larger class, or genus, as a result of a specific difference. In logic, the words genus and species are used as general terms for a large class and a smaller subclass within that larger class, respectively. Different species within the same genus are distinguished from one another because of a specific difference, which is the attribute or set of attributes that makes each species unique. A definition by genus and difference uses both a genus term and one or more difference words that define the definiendum as a species of the larger genus as a result of that attribute connoted by the difference words. Each definition of this type therefore has three parts: the species being defined, the genus of which the species is a subclass, and the difference words that connote the attributes that define the species as distinct from other species within the same genus.
Each definition shown next is a definition by genus and difference. For each definition, identify and indicate the species term, the genus term, and the difference words that make up the definition.