<ontology, metaphysics, accident, existentialism> that without which a specific thing or substance would not be one and the same (type of) individual it is, those features of an object that make it the kind of object it is as opposed to its accidents (e.g. a person's ability to reason is an essential human feature, while hair color would be an accident) - Essentialism is the view that the essence - accident distinction is not arbitrary but rooted in the nature of reality.
based on [A Philosophical Glossary, Philosophical Glossary]
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