Simon Buré

The Many Worlds Interpretation (MWI) of quantum mechanics has been proposed as a framework that vindicates libertarian free will by grounding alternative possibilities in real, physically actual branches of the universal wave function. This paper argues that the appeal is illusory. Libertarianism requires within branch causal openness: the agent’s actual causal history must have been compatible with a different outcome. MWI provides only cross branch plurality: counterparts of the agent act otherwise in numerically distinct branches. We formalise this as the contrast between A type cross branch possibility and B type within branch possibility, and show that the libertarian tradition from Chisholm to Kane has consistently required B. MWI is doubly deterministic: globally, through unitary evolution; locally, through decoherence that seals within branch trajectories well before deliberation can begin on every published estimate of the relevant timescale, and where the most favourable revised estimate is granted, the resulting branching falls to the luck objection. We examine the most sustained recent attempt to extract libertarian free will from MWI, Stoica 2024, three further candidate locations at which within branch openness might be inserted, and Deutsch’s temporal symmetry argument. Each fails at the same structural point: it trades cross branch plurality for within branch openness. We then argue that MWI sustains an enhanced compatibilism, in which counterfactuals are factually rather than hypothetically true and agents’ actions shape the actual distribution of histories across the multiverse, a genuine contribution that nevertheless does not bridge the gap to libertarianism. Libertarians who wish to remain libertarians must look beyond MWI.

This methodological essay develops a methodology for productive dialogue between philosophical aesthetics and empirical research on art. For empiricists, it identifies three standing constraints on how philosophical conclusions can be drawn from data: the normative/descriptive distinction (normative positions cannot be empirically falsified), the is–ought gap (descriptive findings do not on their own license normative conclusions), and the hard problem of consciousness (neural correlates do not resolve phenomenal questions). It derives from these constraints a concrete recommendation: researchers should pre-specify which class of philosophical position is targeted, what prediction distinguishes it from alternatives, and how strong the evidential pressure is. For theorists, it argues that descriptive positions face scalar empirical pressure calibrated by evidence quality, and that normative positions face prescriptive cost rather than falsification. Evidence from five empirical domains—neuroaesthetics, psychology of arts, computational aesthetics, cross-cultural aesthetics, and AI and creativity research —is assessed using this methodology against five classical philosophical debates: ontology, experience, interpretation, value, and creativity. The cross-domain verdict is consistent: extreme positions face strong pressure while intermediate frameworks integrating formal and contextual factors receive support across independent evidence streams.