Until now we have been thinking about objects as if they were givens, that is, immediately present in our personal, or some communal, experience. But what is it which is given ? One particular, concrete thing? (The problem is then abstraction.) A particular color? (The problem is then concretion.) Or a human being? It is essentialists of the metaphysical persuasion who believe that objects (or at least objects of a 'natural kind') have real essences, and that those essences are a prerequisite for identifying them as separate objects. In their view an object is not only always of some particular kind, but 'essentially' always of that one particular kind, normally the species it belongs to if it happens to be a living being. The emphasis on species membership forces metaphysical essentialists to adopt a naively absolutist conception of the notion of species, because each species must be as fixed and as detached from other species as each corresponding 'real essence'. As soon as objects are not of a natural kind (for example, artifacts or even not that), their metaphysics immediately runs short of essentials. (In spite of this, some essentialists maintain that the discovery of real essences would be the ultimate goal of all scientific investigation.) The metaphysical essentialists' belief in fixed, specific quiddities -- not generic or other superspecific ones, and not racial or other subspecific ones -- may be preposterous or nonsensical, there is another element in their belief for which we have to be even more on the alert. It is the underlying supposition that there is merely one way, or merely one adequate way, of describing reality, namely by referring to the fixed essence or essential properties of an object or kind. Describing reality is therefore presented as if it were relevancy-independent, that is, independent of the purpose of describing it. In fact, however, it is the context or the goal(s) of the description which determine which predicates are accidental or not in those circumstances. This is not to say that given a certain description of an object (for example, the natural kind it belongs to) certain attributes are essential whereas others are not. Yet, such a form of essentialism is only of some conventionalist type: all it claims is that if an object is classified in a certain way, it is a convention of language that it must have certain attributes and/or relations and/or component parts which are essential elements of each member of the class mentioned. Thus a human being has certain essential parts and characteristics, and all other parts and predicates are contingent, but nothing forces us to classify an object (even if it is a human being) as a human being: we might classify the thing concerned as a living or sentient being, as a male or female mammal, as a person, as a member of a particular ethnic group, and so on and so forth. Which description we should or should not use, and which properties are essential is, then, context- or relevancy-dependent.

While the metaphysical, 'specific' form of essentialism is too implausible and too deceptive to deserve further consideration here, the problem remains how things are distinguished as separate entities. It seems that we must at least accept some notion of substance from which a thing derives its more or less discrete existence. Attempts to explain objectual existence in the physical world on a phenomenalist basis have failed, but mainly because of a one-sided emphasis on phenomena which are visual. Confining oneself to visual sense experiences exclusively, it is indeed impossible to distinguish spatially discernible individual things. The identification of individual objects in the environment surrounding them is obviously not a question of visual perception in isolation, but rather of intersensory conformity, particularly conformity between visual sensations and simultaneous tactual ones so it seems, and particularly after many repeated experiences in that environment. That is why a fata morgana is not an object in the sense a pen and a finger are objects: altho it may visually be a discernible phenomenon, there is never a tactual, or other nonvisual, sensory experience accompanying it at the same moment as we see it. (This is also why we should not call anonymous phenomena "unidentified flying objects" when people have only 'seen' them and not experienced them in any other way.) As a matter of fact, this hypothesis of intersensory object identification is more of an empirical(-scientific) nature than ontological. It is not the place here to work it out further and to defend it, but it is definitely a more sober and fertile hypothesis than the quasi-explanation of metaphysicians groping for ghostly 'whatnesses'.