Ambiguity of being
The verb ‘to be’ is ambiguous, and can refer to the following relations. This is known as the Frege-Russell theory of ambiguity. The following table (from Hintikka and Vilkko (2006)) demonstrates the different meanings of being.
| use of being | formal expression | informal meaning |
|---|---|---|
| predication | Dog(argo) | Argo is a dog |
| existence | ∃(x) dog(x) | There is a dog |
| identity | jekyll = hyde | Dr. Jekyll is Mr. Hyde |
| subsumption | ∀x Dog(x) → Mammal(x) | A dog is a mammal |
