 ‘Triviality’ may strike one as the wrong word here. After all, there have been and continue to be philosophers who hold radically monistic ontologies—from the Eleatics (Rea 2001) to Spinoza (J. Bennett 1984) all the way to contemporary authors such as Horgan and Potrč (2000), whose comparative ontological parsimony results in the thesis that the whole cosmos is but one huge extended atom, an enormously complex but partless “blobject”. For all we know, it may even be that the best ontology for quantum mechanics, if not for Newtonian mechanics, consists in a lonely atom speeding through configuration-space (Albert 1996). None of this is trivial. However, none of this corresponds to fully endorsing (36), either. For such philosophical theories do not, strictly speaking, assert the existence of one single entity—which is what (36) says—but only the existence of a single material substance along with entities of other kinds, such as properties or spatio-temporal regions. In other words, they only endorse a sortally restricted version of (36). In its full generality, (36) is much stronger and harder to swallow, and most mereologists would rather avoid it. The bottom line, therefore, is that theories endorsing (P.10) are likely to be highly non-standard, pace Carnap's persuasion that the null item would be a “natural and convenient choice” for certain purposes (such as providing a referent for all defective descriptions; see 1947: 37). A few authors have indeed gone that way, beginning with Martin (1943, 1965), who rejects unrestricted Reflexivity and characterizes the null item as “that which is not part of itself”. Other notable exceptions include Bunt (1985) and Meixner (1997) and, more recently, Hudson (2006) and Segal (2014), both of whom express sympathy for the null individual at the cost of foregoing unrestricted (Quasi-)Supplementation. See also Priest (2014a and 2014b: §6.13) and Cotnoir and Weber (2014), who avoid (36) through a paraconsistent recasting of the underlying logic. Still another option would be to treat the null item as a mere algebraic “fiction” and to amend the entire mereological machinery accordingly, carefully distinguishing between trivial cases of parthood and overlap (those that involve the infectious null item) and genuine, non-trivial ones: