Are ‘Identical Quantum Particles’ Weakly Discernible Objects?

Abstract

There is a growing literature in which it is claimed that conventional wisdom, according to which “identical quantum particles” are to be regarded either as objects violating Leibniz’s principle or – preferably from a physical point of view – not as objects at all but rather as field quanta, is incorrect. The claim is that a collection of identical quantum particles is very much like a collection of classical objects in a situation that is perfectly symmetrical (like Black’s spheres). Such classical objects do not possess individual physical properties that distinguish them, but nevertheless obey a version of Leibniz’s principle because of the irreflexive relations that hold between them; they are weakly discernible. In this paper I criticize this analogy. After explaining the notion of weak discernibility I argue that the availability of this notion does not change the interpretational status quo in quantum mechanics.