Abstract

In a recent paper [Carcassi, Oldofredi and Aidala, Found Phys 54, 14 (2024)] it is claimed that the whole Harrigan–Spekkens framework of ontological models is inconsistent with quantum theory. They show this by showing that all pure quantum states in $$\psi$$-ontic models must be orthogonal. In this note, we identify some crucial assumptions that lack physical motivation in their argument to the extent that the main claim is incorrect.