The Principle of the Identity of Indiscernible (PII) in Philosophy of Physics: An Example of Organizing Principles (Departmental Seminar)

Abstract:

In this paper, I discuss three organizing principles: Principle of the Identity of Indiscernible (PII), Determinism, and Locality. These principles together form the foundation of experimental and theoretical physics. Organizing principles are those that must be assumed to be a working hypothesis to perform experiments and interpret their results, and so cannot be affected by results of such experiments: PII (“[t]hings which are different must differ in something or must have within themselves some diversity that can be noted” (L529)) that helps us to identify a physical event as “the same” as another physical event; “Determinism” that tells us that a physical event can pertain to one and only one trajectory of events, hence it allows us to individuate physical events in time; and “Locality” allows us to separate one physical event from another, hence it allows us to individuate physical events in space. My argument and examples only stay in the domain of non-relativistic quantum mechanics. The generalization of the investigation is limited to this realm.

My argument is twofold. First, I will argue that the three pillars above are necessary pre- conditions for experimental and theoretical physics, as they allow us to conduct experiments that underwrite physical laws. Second, I will argue that since these three principles are all principles of what it means to be “the same” (in general, in space, in time), then if one of them fails, all of them fail.

Delivered in English.
All are welcome.