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Modal Expansionism


There are various well-known paradoxes of modal recombination. This paper offers a solution to a variety of such paradoxes in the form of a new conception of metaphysical modality. On the proposed conception, metaphysical modality exhibits a type of indefinite extensibility. Indeed, for any objective modality there will always be some further, broader objective modality; in other terms, modal space will always be open to expansion.


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Thanks to Ben Brast-Mckie, Adrian Moore, and Ted Sider for discussions about earlier versions of this paper, and to Peter Fritz and an anonymous referee for this journal for their helpful and perceptive comments. Special thanks to James Studd and Timothy Williamson for their encouragement and comments on several drafts of this paper.

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Correspondence to Alexander Roberts.

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Roberts, A. Modal Expansionism. J Philos Logic 48, 1145–1170 (2019).

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  • Metaphysical necessity
  • Indefinite extensibility
  • Bimodal logic