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The Ontology of Thisness


  • Earlier versions of this paper were presented at Queen's University Belfast and the University of St Andrews. I am grateful to the audiences at those presentations for their probing questions and insightful comments. I am also grateful to Anna Marmodoro for helpful written comments. The paper was completed while I was on a Templeton Research Fellowship at Hertford College, Oxford. I am grateful to the John Templeton Foundation for funding this period of research, and to Hertford College for providing me with such an ideal environment in which to conduct philosophical research.


This paper seeks to give an account of what it is for an individual to instantiate thisness (i.e. primitive individual essence). Thisnesses are peculiar entities, and even those who endorse their existence and instantiation by objects/entities, have said very little about how an individual and its thisness are related. My approach will be to seek out a model for the instantiation of thisness by canvassing broadly Aristotelian accounts of the substance/attribute relation, and then by making appropriate modifications to the most likely candidates in order to accommodate an individual's instantiation of thisness. What will emerge is that the model with the most utility makes thisness redundant in the case of material substances. Nonetheless, I will suggest that a version of the model can be appropriately applied in the case of other individuals which might instantiate thisness: for example, events (where these are conceived as a fundamental category of ontology distinct from material substances).