Quasi-supplementation, plenitudinous coincidentalism, and gunk

Weak Supplementation (WSP) is the view that if a thing x has a part y with which x is not identical, then x has a part z that does not overlap y. I note that there is a slightly weaker principle, Quasi-Supplementation (QS), which says that that if a thing x has a part y with which x is not identical, then x has at least two parts, z and w, that do not overlap each other. I then argue that QS has WSP’s main virtues while avoiding its main vices. That is the primary aim of this paper. A secondary aim is to explore some potential applications of QS. I note that QS can be used in (i) an argument from a plenitudinous form of coincidentalism to the non-existence of simples and the ‘strong gunkiness’ of all things, (ii) an argument in the other direction—from the possibility of simples to the conclusion that plenitudinous coincidentalism is not necessary, and (iii) arguments for and against certain constituent ontologies, according to which ordinary concrete particulars have formal components.