 The terminology of determinables and determinates stems from ancient and scholastic treatment of the definition of a species, as analyzable into two parts: a genus, or generic part of an essence—the pars determinabilis essentiae, and the differentia, or differentiating part of an essence—the pars determinans essentiae. As we’ll see, the terminology and its original application eventually went separate ways, with the genus-species relation standardly being treated in conjunctive terms (with a given species being identified with the conjunction of a genus and one or more differentia), and determination being treated as a distinctive non-conjunctive specification  relation.[1] 