Essentialism is a theoretical concept denoting a primacy of essences, that is, a permanent, unchanging, and “real” core that lies “behind” temporary, changing appearances. The concept is most commonly understood as a belief in the real, true essence of things, the fixed properties that define a given entity.

Historically, the most common theories of essentialisms are the Platonic doctrine of universal types and the originally Aristotelian doctrine that things in a particular category all have at least one common characteristic without which they could not be members of that category. But the concept is also ambiguous and has inspired a large amount of debate. Locke defined essence in two parts: nominal essence and absolute essence. A nominal essence refers to a conceptual entity defined or produced ...