Quantum metametaphysics

Abstract

Say that metaphysical indeterminacy occurs just when there is a fact such that neither it nor its negation obtains. The aim of this work is to shed light on the issue of whether orthodox quantum mechanics provides any evidence of metaphysical indeterminacy by discussing the logical, semantic, and broadly methodological presuppositions of the debate. I argue that the dispute amounts to a verbal disagreement between classical and quantum logicians, given Eli Hirsch's account of substantivity; but that it need not be so if Ted Sider's naturalnessbased account of substantivity is adopted instead. Given the latter approach, can anything be said in order to tip the balance of the dispute either way? Some prima facie reasonable constraints on naturalness entail that the classicist is right, and the quantum world is therefore determinate. Nevertheless, there are reasons for weakening those constraints, to the effect that the dispute remains very much open. Finally, I discuss alternative accounts of metaphysical indeterminacy, and argue that they are unsuitable for framing the quantum indeterminacy debate.

Derivative Metaphysical Indeterminacy and Quantum Physics

“…Armed with those tools we can now state the idea that, relative to a logical space S, MI amounts to there being no fact of the matter about something (Torza [40]):…”

“…My diagnosis is that what kept philosophers from buying into MI was the lack of suitable concepts that would allow them to theorize about it, rather than any specific argument. 3 The general attitude has indeed changed to some degree now that a number of characterizations of MI have been put forward, as in Akiba [2], Barnes & Williams [7], Darby & Pickup [17], Smith & Rosen [37], Torza [40], and Wilson [45].…”

“…However, there are independent reasons for being skeptical of such approaches, since metaphysical supervaluationism is unable to subsume quantum indeterminacy (Darby[16], Skow[36]), whereas the determinable-based theory has a hard time making sense of a number of phenomena such as the open future, indeterminate identity, and indeterminate existence(Barnes & Cameron [6]). Moreover, it has been argued that the determinablebased account is inadequate in the way it deals with quantum indeterminacy as well(Fletcher & Taylor [23], Torza[40]). For a comparison between the present approach and the determinable-based account see Lewis[27] in this volume.…”