 Different interpretations of this clause run through medieval discussions on consequence, ranging from the 12th to the 15th century and beyond. A number of authors seem to treat the notion of containment in metaphysical and/or semantic terms, while others (in particular the British authors of the second half of the 14th century) lean more heavily towards what appears to be an epistemic interpretation (see section 3.4). And just as (TP) and (ST) still very much inform how most of us think about (logical) consequence, variations of the containment theme, as captured in (Co), remain pervasive among contemporary authors, motivating for example the development of a number of relevance logics (see entry on relevance logic in this encyclopedia). However, notice that (Co) is also interpreted metaphysically by a number of medieval authors; this metaphysical focus is not nearly as present among contemporary philosophers and logicians (with the exception perhaps of some of the recent discussions on the concept of grounding).