, Volume 188, Issue 1, pp 117–142 | Cite as

A future for the thin red line

Open Access


The thin red line (TRL) is a theory about the semantics of future-contingents. The central idea is that there is such a thing as the ‘actual future’, even in the presence of indeterminism. It is inspired by a famous solution to the problem of divine foreknowledge associated with William of Ockham, in which the freedom of agents is argued to be compatible with God’s omniscience. In the modern branching time setting, the theory of the TRL is widely regarded to suffer from several fundamental problems. In this paper we propose several new TRL semantics, each with differing degrees of success. This leads up to our final semantics, which is a cross between the TRL and supervaluationism. We discuss the notions of truth, validity and semantic consequence which result from our final semantics, and demonstrate some of its pleasing results. This account, we believe, answers the main objection in the literature, and thus places the TRL on the same level as any other competing semantics for future contingents.


Future contingents Branching-time Ockhamism Thin red line Supervaluationism 


  1. Barcellan, B., & Zanardo, A. (1999). Actual futures in Peircean branching-time logic. In J. Gerbrandy, M. Marx, M. de Rijke, & Y. Venema (Eds.), JFAK: Essays dedicated to Johan van Benthem on the occasion of his 50th birthday. CD-ROM, available on-line:
  2. Belnap N., Green M. (1994) Indeterminism and the thin red line. Philosophical Perspectives 8: 365–388CrossRefGoogle Scholar
  3. Belnap N., Perloff M., Xu M. (2001) Facing the future: Agents and choices in our indeterministic world. Oxford University Press, New YorkGoogle Scholar
  4. Braüner, T., Halse, P., & Øhrstrøm, P. (1998). Ockhamistic logics and true futures of counterfactual moments. In IEEE temporal representation and reasoning (time-98) proceedings.Google Scholar
  5. Braüner T., Hasle P., Øhstrøm P. (2000) Determinism and the origins of temporal logic. In: Barringer H., Fisher M., Gabbay D., Gough G. (eds) Advances in temporal logic, Vol. 16 of applied logic series. Kluwer Academic Publishers, Dordrecht, pp 185–206Google Scholar
  6. Burgess J. P. (1979) Logic and time. The Journal of Symbolic Logic 44(4): 566–582CrossRefGoogle Scholar
  7. McKim V. R., Davis C. C. (1976) Temporal modalities and the future. Notre Dame Journal of Formal Logic 17(2): 233–238CrossRefGoogle Scholar
  8. Müller, T. (2011). Tense or temporal logic. In L. H. R. Pettigrew (Ed.), The continuum companion to philosophical logic. Continuum.Google Scholar
  9. Øhrstrøm, P. (1981). Problems regarding the future operator in an indeterministic tense logic. In: Danish yearbook of philosophy (Vol. 18, pp. 81–95). Museum Tusculanum Press.Google Scholar
  10. Øhrstrøm P. (1984) Anselm, Ockham and Leibniz on divine foreknowledge and human freedom. Erkenntnis 21: 209–222CrossRefGoogle Scholar
  11. Øhrstrøm P. (2009) In defence of the thin red line: A case for Ockhamism. Humana mente 8: 17–32Google Scholar
  12. Placek, T., & Belnap, N. (2010). Indeterminism is a modal notion: Branching spacetimes and Earman’s pruning. Synthese (in press). doi:10.1007/s11229-010-9846-8.
  13. Placek T., Müller T. (2007) Counterfactuals and historical possibility. Synthese 154(2): 173–197CrossRefGoogle Scholar
  14. Prior A. (1967) Past, present and future. Oxford University Press, OxfordCrossRefGoogle Scholar
  15. Thomason R., Gupta A. (1980) A theory of conditionals in the context of branching time. The Philosophical Review 89(1): 65–90CrossRefGoogle Scholar
  16. Thomason R. H. (1970) Indeterminist time and truth-value gaps. Theoria 36(3): 264–281CrossRefGoogle Scholar
  17. Thomason R. H. (1984) Combinations of tense and modality. In: Gabbay D., Guenthner F. (eds) The handbook of philosophical logic. D. Reidel Publishing Co, Dordrecht, pp 135–165CrossRefGoogle Scholar
  18. Tweedale M. M. (2004) Future contingents and deflated truth-value gaps. Noûs 38(2): 222–265CrossRefGoogle Scholar
  19. Williamson T. (1994) Vagueness. Routledge, LondonGoogle Scholar
  20. Zanardo A. (1996) Branching-time logic with quantification over branches: The point of view of modal logic. Journal of Symbolic Logic 61(1): 1–39CrossRefGoogle Scholar

Copyright information

© The Author(s) 2012

Authors and Affiliations

  1. 1.Department of PhilosophyUniversity of BristolBristolUK
  2. 2.Department of PhilosophyJagiellonian UniversityKrakówPoland

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