Back to the (Branching) Future

  • Giacomo AndreolettiEmail author


The future is different from the past. What is past is fixed and set in stone. The future, on the other hand, is open insofar as it holds numerous possibilities. Branching-tree models of time account for this asymmetry by positing an ontological difference between the past and the future. Given a time t, a unique unified past lies behind t, whereas multiple alternative existing futures lie ahead of t. My goal in this paper is to show that there is an incompatibility between the way branching-tree models account for the open future and the possibility of time travel. That is, I argue that once time travel enters the picture, branching time fails to model the openness of the future by means of alternative future branches. I show how this holds independently of whether branching-time models are cashed out in A-theoretic or B-theoretic terms.


Open future Branching time Time travel A-theory B-theory 



I thank an anonymous referee of this journal and the audience at the conference Modal Metaphysics Issues on the (Im)possible VI for helpful comments on earlier drafts of this paper.

Compliance with Ethical Standards

Conflict of Interest

The author declares that there is no conflict of interest.


  1. Baron, S. (2017). Back to the unchanging past. Pacific Philosophical Quarterly, 98(1), 129–147.CrossRefGoogle Scholar
  2. Belnap, N. (1992). Branching space-time. Synthese, 92(3), 385–434.CrossRefGoogle Scholar
  3. Broad, C. D. (1923). Scientific thought. New York: Harcourt, Brace and Co..Google Scholar
  4. Grandjean, V. (2019). How is the asymmetry between the open future and the fixed past to be characterized? Synthese.
  5. Lewis, D. (1976). The paradoxes of time travel. American Philosophical Quarterly, 13, 145–152.Google Scholar
  6. Lewis, D. (1979). Counterfactual dependence and time’s arrow. Noûs, 13(4), 455–476.CrossRefGoogle Scholar
  7. Lewis, D. (1986). On the plurality of worlds. Oxford: Blackwell publishers.Google Scholar
  8. Loss, R. (2015). How to change the past in one-dimensional time. Pacific Philosophical Quarterly, 96(1), 1–11.CrossRefGoogle Scholar
  9. MacFarlane, J. (2003). Future contingents and relative truth. The Philosophical Quarterly, 53(212), 321–336.CrossRefGoogle Scholar
  10. MacFarlane, J. (2008). Truth in the garden of forking paths. In M. Kölbel & M. Garcı́a-Carpintero (Eds.), Relative truth (pp. 81–102). Oxford: Oxford University Press.CrossRefGoogle Scholar
  11. Markosian, N. (1995). The open past. Philosophical Studies, 79(1), 95–105.CrossRefGoogle Scholar
  12. Martinez, M. (2011). Travelling in branching time. Disputatio, 4(31), 271–287, 2011.CrossRefGoogle Scholar
  13. McCall, S. (1994). A model of the universe: space-time, probability, and decision (p. 1994). Oxford: Oxford University Press.Google Scholar
  14. Miller, K. (2005). Time travel and the open future. Disputatio, 1(19), 223–232.CrossRefGoogle Scholar
  15. Norton, J. (2018). If time travel to our location is possible, we do not live in a branching universe. Analysis, 78(2), 260–266.CrossRefGoogle Scholar
  16. Prior, A. (1967). Past, present and future. Oxford: Clarendon Press.CrossRefGoogle Scholar
  17. Torre, S. (2011). The open future. Philosophy Compass, 6(5), 360–373.CrossRefGoogle Scholar
  18. van Inwagen, P. (2010). Changing the past. In D. W. Zimmerman (Ed.), Oxford studies in metaphysics (Vol. 5, pp. 3–28). Oxford: Oxford University Press.Google Scholar
  19. Wasserman, R. (2017). The paradoxes of time travel. Oxford: Oxford University Press.Google Scholar

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© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.University of TyumenTyumenRussian Federation

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