Contextuality, Nonlocality and Counterfactual Arguments

Abstract In this paper, following an elementary line of thought which somewhat differs from the usual one, we prove once more that any deterministic theory predictively equivalent to quantum mechanics unavoidably exhibits a contextual character. The purpose of adopting this perspective is that of paving the way for a critical analysis of the use of counterfactual arguments when dealing with nonlocal physical processes. One of us (G.C.G) dedicates this paper to the colleague and friend Pekka Lahti with whom he had many stimulating scientific and human interactions.