It has often been suggested that similar quantum particles may be a counterexample to the principle of the Identity of Indiscernibles. In this article, I discuss the status of indiscernibility in a perspectival approach to quantum mechanics. I argue that adopting an internal physical perspective can have the effect of making entities discernible even if they are not discernible relative to external reference frames, and thus perspectivalism offers a new way to understand the physical meaning of weak discernibility. I discuss whether this approach is circular, and I consider whether the reference frames involved are physically meaningful. I conclude that the Identify of Indiscernibles can probably be maintained in this context, though there are outstanding questions pertaining to the meaning of the quantum state and the way in which a system should be represented in its own reference frame.
Emily Adlam (Tue,) studied this question.