Full Idea
Essentialism for a class of entities is that for one entity and a condition which it fulfills, the question of whether it necessarily fulfills the condition has a definite answer apart from the way the entity is specified.
Gist of Idea
Essentialism is the existence of a definite answer as to whether an entity fulfils a condition
Source
Allan Gibbard (Contingent Identity [1975], VII)
Book Reference
-: 'Journal of Symbolic Logic' [-], p.207
A Reaction
Yet another definition of essentialism, but resting, as usual in modern discussions, entirely on the notion of necessity. Kit Fine's challenge is that if you investigate the source of the necessity, it turns out to be an essence.
Related Idea
Idea 14077 Essentialism for concreta is false, since they can come apart under two concepts [Gibbard]