Quantum Ontology and Extensional Mereology

Abstract

The present paper has three closely related aims. We first argue that Agazzi's scientific realism about Quantum Mechanics is in line with Selleri's and Tarozzi's proposal of Quantum Waves. We then go on to formulate rigorously different metaphysical principles such as property compositional determinateness and mereological extensionalism. We argue that, contrary to widespread agreement, realism about Quantum Mechanics actually refutes only the former. Indeed we even formulate a new quantum mechanical argument in favor of extensionalism. We conclude by noting that, given the results of the work, Agazzi's particular attitude towards Quantum Mechanics is still one of the most promising theoretical perspectives.

What does “nothing over and above its parts” actually mean?

“…However, it should be noted that if we assume that such a system has two parts, x and y , then all mereology tells us is that the sum of x and y is a particular object that overlaps with all and only those things that overlap with x and y . Whether this sum has any of the properties had by x and y and whether this sum is reducible to x and y is all left undecided by the theory and arguably needs to be answered on a case by case basis using empirical methods (Calosi, Fano, & Tarozzi, , 1750).…”

‘Identity’ as a mereological term

“…He does not, however, think this is an additional ideological cost because everyone will have to accept set theory-except when Hartry Field's (1980;1989) program for a nominalistic mathematics turns out to be successful (Sider 2013, 286ff). I will not dwell on this point here, but simply flag it to point out that anyone who accepts mereology and thinks she can do without set theory could point out 16 That the systems quantum mechanics speaks of can be viewed as mereological wholes is argued for by Calosi, Fano, and Tarozzi (2011); and Calosi and Tarozzi (2014). Cf.…”