| Consider as a definiendum a universal, such as man, and its definiens, rational animal. |
| To make sure that the extension of the definiens matches that of the definiendum, Beardsley thinks, the second disjunct of the definition is needed. |
| He required of definition that the definiens should be synonymous with the definiendum but contain no terms in common with it. |
| According to the third requirement, definiens and definiendum must be co-extensive, but only a single definiens provides the specific denotation of the definiendum. |
| Elsewhere Aristotle asserts or implies that all atomic premises are definitions, with the middle term serving as the definiens. |
| The former is defined, by the ancient logic texts I love, as when a definition uses the same terms in the definiens as in the definiendum. |
