 If definite plural and mass NPs and conjunctions of definite NPs stand for sums, they do not impose any restrictions on sum formation, which means that the ontology of natural language displays mereological universalism (see entry on  mereology).  Mereological universalism is generally not taken to obtain for the ontology of ordinary objects, where sum formation appears subject to conditions of integrity (such as having a form or boundary) that the potential sum must fulfill (Simons 1987) or by teleological conditions of purpose (Rose &amp; Schaffer 2017)  (§1.5).  Such restrictions need not obtain for sum formation in the ontology of the real or fundamental, where mereological universalism is a plausible view.