Lisbon Philosophy of Physics Seminars: Cristian Mariani (8 June on Zoom)

On Wednesday 8 June Cristian Mariani (University of Barcelona) will give a talk titled “Does the Primitive Ontology of GRW rest on Shaky Ground?” (abstract below).
The series of online seminars is organized in the context of the activities of the LanCog Research Group at the Centre of Philosophy of the University of Lisbon, and will focus on the foundations of quantum and spacetime physics.

The meeting will be online on Zoom (17:00-19:00 CEST). If you have not registered yet, you can do so here.

You can address any question to Andrea Oldofredi (



The notion of Primitive Ontology (PO) has recently received a great deal of attention in the quantum foundations literature. The PO is the fundamental ontology posited by a certain theory, what is out there in the world which makes the predictions of theory true. Can we make sense of the idea that the PO is indeterminate? And if we do, would this idea be explanatory useful in some way, or would it simply lead us too far from the very reasons we had to posit a PO in the first place? As I will show in this paper, these issues become of crucial importance when it comes to understanding what the ontology of the Mass Density approach to GRW (GRWm) ultimately looks like. Proponents of the PO are never explicit in claiming that the determinacy is a requirement for the notion, yet arguably this is entailed by one of the criteria for a suitable PO, namely its being always well defined in every point in 3D space. I will argue that this requirement is however not satisfied in GRWm. The conclusion I will draw is that the notion of indeterminate PO should be taken seriously, for it is suggested by one the major interpretations of quantum mechanics.