In reality, what they call “the entirety of the essence,” “a part of the essence,” and “an entailment of the essence” simply corresponds to the three modes of semantic indication: direct denotation, implicative inclusion, and necessary entailment. Whatever a person intends by a given term constitutes the full object of his intent, the complete signification, and the whole essence that exists in his mind and for which he has employed that word. Whatever forms only a portion of that meaning—signified by implicative inclusion—is likewise only a part of what he intends and a part of the notional essence present within him. As for what is merely entailed by the term, it lies outside the denotation itself, yet remains necessarily connected to it; it therefore stands outside the notional essence while remaining inseparable from it.

This topic has been treated at length in works on logic, and this is not the place to rehearse it in detail; my purpose here is merely to point it out. Anyone who carefully examines their discourse on intrinsic, constitutive attributes that enter into the quiddity, and on necessary attributes that lie outside the quiddity; who studies their more extensive writings in this field; who gives rational inquiry its due and does not accept expressions whose meanings he has not verified—such a person will see clearly that the distinctions they draw between the essential and the necessary accidental, their claim that the real entity is composed of genus and differentia, that one of these is the “shared essential,” the other the “distinguishing essential,” and that their combination yields the species; and likewise their division of the accidental into the “common accident” and the “proprium”—all of this ultimately reduces to mental constructs. It is a composition that exists only in the mind, not in external reality; it follows what a person conceives and articulates, not the things as they actually are. Thus, one who conceptualizes a “rational animal” will regard “animal” as the shared essential and “rational” as the distinguishing essential, while “laughing” lies outside his conception. But if he conceives of a “laughing animal,” the situation is reversed: “laughing” becomes essential within that conception, and “rational” falls outside the essence.