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Peacocke’s Principle-Based Account of Modality: “Flexibility of Origins” Plus S4


Due to the influence of Nathan Salmon’s views, endorsement of the “flexibility of origins” thesis is often thought to carry a commitment to the denial of S4. This paper rejects the existence of this commitment and examines how Peacocke’s theory of the modal may accommodate flexibility of origins without denying S4. One of the essential features of Peacocke’s account is the identification of the Principles of Possibility, which include the Modal Extension Principle (MEP), and a set of Constitutive Principles. Regarding their modal status, Peacocke argues for the necessity of MEP, but leaves open the possibility that some of the Constitutive Principles be only contingently true. Here, I show that the contingency of the Constitutive Principles is inconsistent with the recursivity of MEP, and this makes the account validate S4. It is also shown that, compatibly with the necessity of the Constitutive Principles, the account can still accommodate intuitions about flexibility of origins. However, the account we end up with once those intuitions are consistently accommodated may not be satisfactory, and this opens up the debate about whether or not artefacts allow for some variation in their origins.

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  1. Fine, K.: 1994, ‚Essence and Modality’, in Philosophical Perspectives 8, Logic and Language, 1–16

  2. Peacocke C. (1999) Being Known. Oxford University Press, Oxford

    Google Scholar 

  3. Peacocke, C.: 2001, ‚The Past, Necessity, Externalism and Entitlement', in Philosophical Books, Blackwell Publishers, pp. 106–117

  4. Peacocke C. (2002a) The Principle-based Account of Modality: Elucidations and Resources. Philosophy and Phenomenological Research LXIV(3):663–679

    Google Scholar 

  5. Peacocke C. (2002b) Principles for Possibilia. Noûs 36(3):486–508

    Google Scholar 

  6. Peacocke C. (2002c) Précise on Being Known. Philosophy and Phenomenological Research LXIV(3):636–640

    Google Scholar 

  7. Salmon N. (1981) Reference and Essence. NJ: Princeton University Press, Princeton

    Google Scholar 

  8. Williamson T. (1990) Identity and Discrimination. Basil Blackwell, Oxford

    Google Scholar 

Download references


Earlier drafts of this paper were presented at different events at the University of Tarragona, the University of St. Andrews and the University of Geneva. I wish to thank the audiences on those occasions and the respective commentators, Manolo Garcés, Marcus Rossberg and Davor Bodrožić, for helpful comments and suggestions. Special thanks to Manuel García-Carpintero, Bob Hale and Dan López de Sa, for helpful suggestions and stimulating discussions on the topic. I am also indebted to Christopher Peacocke and an anonymous referee for this journal for their helpful points and improving suggestions. The paper was written with financial support from the Spanish Ministry of Education.

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Correspondence to Sonia Roca Royes.

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Royes, S.R. Peacocke’s Principle-Based Account of Modality: “Flexibility of Origins” Plus S4. Erkenntnis 65, 405–426 (2006).

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  • Actual World
  • Accessibility Relation
  • Constitutive Principle
  • Atomic Concept
  • Individual Essence