"Haecceity" is a term from medievalscholastic philosophy, first coined by followers of Duns Scotus to denote a concept that he seems to have originated: the discrete qualities, properties or characteristics of a thing that make it a particular thing. Haecceity is a person's or object's thisness, the individualising difference between the concept "a man" and the concept "Socrates".
Etymology
Haecceity is a literal translation of the equivalent term in Aristotle's Greekto ti esti or "the what is." Charles Sanders Peirce later used the term as a non-descriptive reference to an individual.
Quiddity
Haecceity may be defined in some dictionaries as simply the "essence" of a thing, or as a simple synonym for quiddity or hypokeimenon. However, the term is sometimes used differently in philosophy. Whereas haecceity refers to aspects of a thing that make it a particular thing, quiddity refers to the universal qualities of a thing, its "whatness", or the aspects of a thing it may share with other things and by which it may form part of a genus of things. Duns Scotus makes the following distinction: While terms such as haecceity, quiddity, noumenon and hypokeimenon all evoke the essence of a thing, they each have subtle differences and refer to different aspects of the thing's essence. Haecceity thus enabled Scotus to find a middle ground in the debate over universals between Nominalism and Realism.
Sociology and philosophy
The social construction of reality, ethnomethodology, and conversation analysis are the main streams that elaborated during the 1960s a new kind of sociology—which influenced later sociology, philosophy, and political analysis. Harold Garfinkel is the founder of ethnomethodology, and teacher of Harvey Sacks, one of the founders of conversation analysis. He used the word haecceity in his seminal Studies in Ethnomethodology, to enhance the indexical inevitable character of any expression, behavior or situation. According to him, the members display the social order they refer to within the settings of the situation they contribute to define. The study of particular situations in their "haecceity" — aimed at disclosing the ordinary, ongoing social order that is constructed by the members and their practices — is the object of ethnomethodology. In his famous paper generally referred to as "Parson's Plenum", Garfinkel used the term "Haecceities" to indicate the importance of the infinite contingencies in both situations and practices. Garfinkel was drawing on phenomenology and Edmund Husserl, logic and Bertrand Russell, and perception theory and Nelson Goodman. Phenomenology is the field of studying the phenomena as such, and can thus be seen as a contemporary philosophical version of the medieval concept of haecceity. Gilles Deleuze uses the term to denote entities that exist on the plane of immanence. The usage was likely chosen in line with his esoteric concept of difference and individuation, and critique of object-centered metaphysics.
Influence
drew on Scotus — whom he described as “of reality the rarest-veined unraveller” — to construct his poetic theory ofinscape. James Joyce made similar use of the concept of haecceitas to develop his idea of the secular epiphany. James Wood refers extensively to haecceitas in developing an argument about conspicuous detail in aesthetic literary criticism.
