Later followers of Scotus called this principle haecceity or'thisness '.
A haecceity or individual essence is a property that only a single object instantiates.
Haecceity thus enabled Scotus to find a middle ground in the debate over universals between Nominalism and Realism.
This is at the heart of Scotist realism, particularly at the theories of haecceity and formal distinction.
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.
Another way to explain a haecceity is to distinguish between " suchness " and " thisness ", where thisness has a more demonstrative character.
Similarly, the distinction between the'thisness'or " haecceity " of a thing and its existence is intermediate between a real and a conceptual 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.
In his famous paper generally referred to as " Parson's Plenum " ( 1988 ), Garfinkel used the term " Haecceities " to indicate the importance of the infinite contingencies in both situations and practices.
Nicknamed " Doctor Subtilis " ( " the subtle doctor " ), he is well known for the " univocity of being, " the formal distinction, and the idea of haecceity.