Comment on Healey’s “Quantum Theory and the Limits of Objectivity”

Abstract

In this comment we critically review an argument against the existence of objective physical outcomes, recently proposed by Healey [1]. We show that his gedankenexperiment, based on a combination of “Wigner’s friend” scenarios and Bell’s inequalities, suffers from the main criticism, that the computed correlation functions entering the Bell’s inequality are in principle experimentally inaccessible, and hence the author’s claim is in principle not testable. We discuss perspectives for fixing that by adapting the proposed protocol and show that this, however, makes Healey’s argument virtually equivalent to other previous, similar proposals that he explicitly criticises.