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Freedom, self-prediction, and the possibility of time travel

  • Alison Fernandes
Article

Abstract

Do time travellers retain their normal freedom and abilities when they travel back in time? Lewis, Horwich and Sider argue that they do. Time-travelling Tim can kill his young grandfather, his younger self, or whomever else he pleases—and so, it seems can reasonably deliberate about whether to do these things. He might not succeed. But he is still just as free as a non-time traveller. I’ll disagree. The freedom of time travellers is limited by a rational constraint. Tim can’t reasonably deliberate on killing his grandfather, certain that he’ll fail. If Tim follows his evidence, and appropriately self-predicts, he will be certain he won’t kill his grandfather. So if Tim is both evidentially and deliberatively rational, he can’t deliberate on killing his grandfather. This result has consequences. Firstly, it shows how evidential limits in the actual world contribute to our conception of the future as open. Secondly, it undercuts arguments against the possibility of time travel. Thirdly, it affects how we evaluate counterfactuals in time travel worlds, as well as our own. I’ll use the constraint to motivate an evidential and temporally neutral method of evaluating counterfactuals that holds fixed what a relevant deliberating agent has evidence of, independently of her decision. Using this method, an agent’s local abilities may be affected by what happens globally at other times, including the future.

Keywords

Time travel Freedom Deliberation Causation Counterfactuals Time asymmetry 

Notes

Acknowledgements

I would like to thank the following people for helpful comments, discussions and suggestions: David Albert, Achille Varzi, Nina Emery, Daniel Nolan, David Braddon-Mitchell, Mike Hicks, Zee Perry, Helen Beebbee, Robbie Williams, Tom Dougherty, Tim Button, Lukas Skiba, Nick Gorman, and audiences at the Joint Session, the Pacific APA, and the International Association for the Philosophy of Time Conference. This work was supported by a Postdoctoral Fellowship at the Center for Philosophy of Science, University of Pittsburgh and a Research Fellowship at the University of Warwick on an Arts and Humanities Research Council project ‘Time: Between Metaphysics and Psychology’ (AH/P00217X/1).

References

  1. Albert, D. (2000). Time and chance. Cambridge, MA: Harvard University Press.Google Scholar
  2. Arntzenius, F., & Maudlin, T. (2013). Time travel and modern physics. In Edward N. Zalta (Ed.) The stanford encyclopedia of philosophy (Winter 2013 Edition), http://plato.stanford.edu/archives/win2013/entries/time-travel-phys/.
  3. Black, M. (1956). Why cannot an effect precede its cause? Analysis, 16, 49–58.CrossRefGoogle Scholar
  4. Blanchard, T. (2014). Causation in a Physical World. PhD Thesis. Rutgers University.Google Scholar
  5. Bratman, M. (1984). Two faces of intention. The Philosophical Review, 93(3), 375–405.CrossRefGoogle Scholar
  6. Davidson, D. (1980). Essays on actions and events. Oxford: Clarendon Press.Google Scholar
  7. Dennett, D. (1984). Elbow room. Cambridge, MA: MIT Press.Google Scholar
  8. Dummett, M. (1964). Bringing about the past. Philosophical Review, 73, 338–359.CrossRefGoogle Scholar
  9. Fernandes, A. (2016a). Varieties of epistemic freedom. Australasian Journal of Philosophy, 94(4), 736–751.CrossRefGoogle Scholar
  10. Fernandes, A. (2016b). A deliberative account of causation: How the evidence of deliberating agents accounts for causation and its temporal direction. PhD Thesis. Columbia University.Google Scholar
  11. Fernandes, A. (2017). A deliberative approach to causation. Philosophy and Phenomenological Research, 95(3), 686–708.CrossRefGoogle Scholar
  12. Fernandes, A. (2018). Time travel and counterfactual asymmetry. (unpublished manuscript).Google Scholar
  13. Fernandes, A. (2019). Time, flies, and why we can’t control the past. In B. Loewer, E. Winsberg, B. Weslake (Eds.), Time’s arrows and the probability structure of the world. Cambridge, MA: Harvard University Press (in press).Google Scholar
  14. Ginet, C. (1962). Can the will be caused? The Philosophical Review, 71(1), 49–55.CrossRefGoogle Scholar
  15. Grice, H. P. (1971). Intention and uncertainty. Proceedings of the British Academy, 57, 263–279.Google Scholar
  16. Hampshire, S., & Hart, H. L. A. (1958). Decision, intention and certainty. Mind, 67(265), 1–12.CrossRefGoogle Scholar
  17. Harman, G. (1976). Practical reasoning. The Review of Metaphysics, 29(3), 431–463.Google Scholar
  18. Holton, R. (2006). The act of choice. Philosophers’ Imprint, 6(3), 1–15.Google Scholar
  19. Horwich, P. (1987). Asymmetries in time. Cambridge MA: MIT Press.Google Scholar
  20. Ismael, J. (2003). Closed causal loops and the bilking argument. Synthese, 136, 305–320.CrossRefGoogle Scholar
  21. Ismael, J. (2007). Freedom, compulsion and causation. Psyche, 13(1), 1–11.Google Scholar
  22. Ismael, J. (2011). Temporal experience. In C. Callender (Ed.), The Oxford handbook of philosophy of time. Oxford: Oxford University Press.Google Scholar
  23. Kapitan, T. (1986). Deliberation and the presumption of open alternatives. The Philosophical Quarterly, 36(143), 230–251.CrossRefGoogle Scholar
  24. Kiourti, I. (2008). Killing baby suzy. Philosophical Studies, 139(3), 343–352.CrossRefGoogle Scholar
  25. Levi, I. (1980). The enterprise of knowledge. Cambridge, MA: MIT Press.Google Scholar
  26. Levi, I. (1986). Hard choices. Cambridge: Cambridge University Press.CrossRefGoogle Scholar
  27. Lewis, D. (1976). The paradoxes of time travel. American Philosophical Quarterly, 13, 145–152.Google Scholar
  28. Lewis, D. (1979). Counterfactual dependence and time’s arrow. Noûs, 13(4), 455–476.CrossRefGoogle Scholar
  29. Loewer, B. (2007). Counterfactuals and the second law. In H. Price & R. Corry (Eds.), Causation, physics, and the constitution of reality. New York: Oxford University Press.Google Scholar
  30. Mellor, D. Hugh. (1998). Real time II. London: Routledge.CrossRefGoogle Scholar
  31. Owens, D. (2008). Deliberation and the first person. In A. E. Hatzimoysis (Ed.), Self-knowledge. Oxford: Oxford University Press.Google Scholar
  32. Pearl, J. (2000). Causality: Models, reasoning and inference. Cambridge: Cambridge University Press.Google Scholar
  33. Price, H. (1991). Agency and probabilistic causality. British Journal for the Philosophy of Science, 42, 157–176.CrossRefGoogle Scholar
  34. Price, H. (1996). Time’s arrow & archimedes’ point. New York: Oxford University Press.Google Scholar
  35. Prosser, S. (2016). Experiencing time. New York: Oxford University Press.CrossRefGoogle Scholar
  36. Rennick, S. (2015). Things mere mortals can do, but philosophers can’t. Analysis, 75(1), 22–26.CrossRefGoogle Scholar
  37. Sider, T. (2002). Time travel, coincidences and counterfactuals. Philosophical Studies, 110, 115–138.CrossRefGoogle Scholar
  38. Smith, N. J. J. (1997). Bananas enough for time travel? British Journal for the Philosophy of Science, 48, 363–389.CrossRefGoogle Scholar
  39. Smith, N. J. J. (2005). Why would time travellers try to kill their younger selves? Monist, 88(3), 388–395.CrossRefGoogle Scholar
  40. Vihvelin, K. (1996). What time travelers cannot do. Philosophical Studies, 81, 315–330.CrossRefGoogle Scholar
  41. Wheeler, J., & Feynman, R. (1949). Classical electrodynamics in terms of direct interparticle action. Reviews of Modern Physics, 21, 425–434.CrossRefGoogle Scholar
  42. Woodward, J. (2003). Making things happen. New York: Oxford University Press.Google Scholar

Copyright information

© Springer Nature B.V. 2018

Authors and Affiliations

  1. 1.Department of PhilosophyTrinity College DublinDublin 2Ireland

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