Two arguments are offered here for postulating individual essences of concrete individuals on top of their sortal essences. One is the explanatory gap argument, the other draws on the analogy with the individual essences of events presupposed in single causal explanations. These arguments support qualitative individual essences with explanatory goals as opposed to hybrid impure relational essences accounting for origin and numerical identity. It is highlighted why origin properties as parts of impure relational essences do not yield genuine de re (...) constructions. The distinction between the two types of individual essences is traced back to the ambiguity of the very notion of individuation. (shrink)

The distinction between essential versus accidental properties has been characterized in various ways, but it is currently most commonly understood in modal terms: an essential property of an object is a property that it must have, while an accidental property of an object is one that it happens to have but that it could lack. Let’s call this the basic modal characterization, where a modal characterization of a notion is one that explains the notion in terms of necessity/possibility. In the (...) characterization just given of the distinction between essential and accidental properties, the use of the word “must” reflects the fact that necessity is invoked, while the use of the word “could” reflects that possibility is invoked. The notions of necessity and possibility are interdefinable: to say that something is necessary is to say that its negation is not possible; to say that something is possible is to say that its negation is not necessary; to say that an object must have a certain property is to say that it could not lack it; and to say that an object could have a certain property is to say that it is not the case that it must lack it. (shrink)