AV¶ÌÊÓƵ

Locating Parts and Wholes

30 May 2025

AV¶ÌÊÓƵ, Espace Colladon (Rue Jean-Daniel-Colladon 2)

Abstracts:

Aaron Cotnoir, "Harmonious Multilocation"

Mereological harmony principles have nearly always been formulated assuming a ban on multilocation. Using an appendix to Uzquiano 2011b as a starting point, I identify several problems that any theory of harmony compatible with multilocation will have to address. These problems suggest a new formulation of harmony principles. I then show how these new harmony principles avoid the above problems, and how they are compatible with classical mereology (thus avoiding all the formal objections raised by Donnelly 2010 and Kleinschmidt 2011). I close by outlining some takeaway lessons multilocation theorists.

Nikk Effingham, "An Exegenic Theory of Location"

There are putative scenarios in which (i) objects are located without being exactly located anywhere, and/or (ii) objects exactly occupy multiple regions. A central aim in the philosophy of location has been to develop a unified theory accommodating both types of cases. After briefly reviewing existing theories and their limitations, I introduce a new account—the exegenic theory—which incorporates the grounding relation to allow for the full range of problematic scenarios. I conclude by reflecting on where this leaves us: Because the relevant grounding relations are not conceptually necessary, the theory cannot account for the conceptual possibility of these scenarios; nonetheless, it is suitable if we restrict our focus to what is metaphysically possible.

Maria Nørgaard, "Locating Composite Quantum Systems"

Traditional theories of location do not easily extend their application to the quantum domain. Notably, as I will argue, approaches by Pashby (2016) and Glick (2022) fail to distinguish between the locations of composite systems and their components. In this talk, I show that the graded quantum location framework (Nørgaard, 2025) offers a promising alternative, distinguishing the location of multi-particle systems from their single-particle subsystems via their  “quantum footprints” – tracking how different systems occupy the same region in different ways. I show how, given a spatial partition, viable regions of location for composite systems emerge from the possible configurations of their parts. I also propose a graded location harmony principle governing the relationship between the location of wholes and parts and explain how this principle breaks down in cases of position entanglement.

Matteo Plebani, "Parts of Structures"

The question of what the parts of a class are has received considerable attention. By contrast, the question of what the parts of an abstract mathematical structure are has been largely neglected. I argue that addressing this question is important for advancing the current debate on mathematical structuralism. I also defend a natural answer: the parts of a structure are its substructures, i.e., the structures that can be embedded in it. A consequence of this view is that the relation between a structure and its parts fails to satisfy key mereological principles, including antisymmetry and virtually all supplementation principles. This highlights a significant difference between structures and other kinds of abstract entities, such as classes, whose parthood relation conforms to the axioms of classical mereology (at least under a standard Lewisian account).

Annica Vieser, "Mereological Location Emergence"

This talk investigates what I will call mereological location emergence, exemplified in recent discussions of mereological approaches to spacetime emergence in quantum gravity. Mereological location emergence occurs in situations of the following sort: We are confronted with two kinds of objects, K₁ and K₂; K₁-objects come with K₁-locations; K₂-objects are parts of K₁-objects, and more strongly even, the K₂-objects build up K₁-objects (in a sense to be specified); yet the K₂-objects lack K₁-locations (again, in a sense to be specified). I begin by identifying formal constraints on the mereological principles that can hold in such scenarios. Then I discuss different ways to fill in the specifications that were missing above. Returning to the example of spacetime emergence in quantum gravity, I reconsider the prevailing interpretation of the situation according to which the underlying quantum gravity entities are not even weakly located anywhere in spacetime.

Organization:

Claudio Calosi (Ca' Foscari, Venice) and Fabrice Correia (Geneva)