Abstract Einstein, Podolsky, and Rosen (EPR) argued that quantum mechanics was incomplete. We consider their argument and the physical and philosophical intuitions that motivated it. Among their intuitions was a commitment to real physical properties and to local properties and interactions. For his part, Einstein’s commitment to locality was closely related to how he understood special relativity. We show why the standard collapse formulation of quantum mechanics is flatly incompatible with special relativity. Following Bell, we then see why no physical theory that satisfies EPR’s commonsense and philosophical intuitions can be empirically adequate over quantum phenomena.