The idea that particular things have essences which serve to identify them as the particular things that they are. Such a belief and premise is often found in archaeology: society itself or types of society, for example, may be held to have an ‘essence’ (though it may not be termed such) which is expressed in what archaeologists observe. Essentialism is most often associated with abstraction: the essential features of a society are identified abstractly (perhaps in theory) and empirical expressions of the set of abstracted essential features sought. Typology and artifact classification may also tend to essentialism if the categories used to identify artifacts are treated abstractly and if the origins and meanings of the categories or taxa are not fully considered.

Essentialism is usually a term of criticism in archaeology because of the metaphysical problem it introduces of the origin of the essences: if society is essentially a functioning system of patterned behaviours (a position held by some processual archaeologists), what is the origin of this necessary logic; why is society necessarily like this? The abstract categories of essentialism also belittle human agency: can society exist as a set of essential features prior to its human subjects? Opponents of essentialism would usually stress human agency: the origin of those categories treated abstractly as essences is to be found in social practice. So society is a human construction, as is ‘the past’, as are the categories we use to understand societies in the past; there is no abstracted or logical and neutral necessity to any of them.