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Does luck exclude knowledge or certainty?


A popular account of luck, with a firm basis in common sense, holds that a necessary condition for an event to be lucky, is that it was suitably improbable. It has recently been proposed that this improbability condition is best understood in epistemic terms. Two different versions of this proposal have been advanced. According to my own proposal (Steglich-Petersen in Synthese 176(3):361–377, 2010), whether an event is lucky for some agent depends on whether the agent was in a position to know that the event would occur. And according to Stoutenburg (Episteme 12(3):319–334, 2015, Synthese, 1–15, 2018), whether an event is lucky for an agent depends on whether the event was guaranteed or certain to occur in light of the agent’s evidence. In this paper, I argue that we should prefer the account in terms of knowledge over that in terms of evidential certainty.

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  1. 1.

    For discussion of this ‘significance condition’ on luck, see e.g. Ballantyne (2012).

  2. 2.

    For a helpful recent review of the debate, see Broncano-Berrocal (2016). For a general discussion of the methodology driving this and similar debates, see Praëm and Steglich-Petersen (2015).

  3. 3.

    Stoutenburg’s statement of the condition has been altered slightly for ease of presentation. He first states the embedded necessary and sufficient conditions for an event to be improbable, and then states that satisfying this is necessary for an event to be lucky. Here, I state both in a single condition.

  4. 4.

    Hales’ cases of skilful luck are those where theories of luck allegedly misclassify events as lucky, when they are really attributable to skill. For example, Ty Cobb, the best hitter in baseball history, averaged .367 over his career, but it was nevertheless improbable for any particular at-bat that he would get a hit. All theories of luck, including the epistemic one, would thus classify his hits as lucky, which Hales claims to be implausible. However, as Stoutenburg convincingly argues, this is in fact the right classification. Luck is a matter of degree, and at least some degree of luck was involved every time Cobb got a hit. Skill can reduce the degree of luck, but does not necessarily eliminate it (2018: pp. 10–12).

  5. 5.

    Hales’ cases of diachronic luck show that our attributions of luck sometimes depend on whether the event is considered in isolation or in relation to other events. For example, the record-breaking shot in a series of basketball free-throws seems luckier than the previous shots in the series. But all of the shots were equally likely to go in when seen in isolation, which seems to force probabilistic accounts, including the epistemic one, to count all of the shots as equally lucky. Stoutenburg argues that this can be explained in terms of the significance condition, since the record-breaking shot was of greater significance to the shooter (2018: pp. 12–13). As noted by an anonymous reviewer, it might be objected that all of the shots were equally necessary for breaking the record. But this does not prevent that more is at stake with the last shot (or the farther into the series one gets), since it is rare to get a single shot which by itself can make the difference between breaking the record or not.

  6. 6.

    That is not to say that there are no remaining problems for the account. An anonymous reviewer objects that on the epistemic account, and perhaps especially the knowledge account, everything will be a matter of luck to creatures that are not capable of having knowledge. The force of this objection depends on (i) what creatures we are willing to attribute luck to, and (ii) what creatures we are willing to attribute knowledge to. Since we routinely attribute knowledge to a wide range of animals, and there seems to be a lower bound to the organisms that we attribute luck to (can snails be lucky? What about bacteria?), there is reason to expect a reasonable overlap between (i) and (ii).

  7. 7.

    There may be room for doubt about Hales’ verdicts. In particular, as Hales himself notes (2016: p. 497), while both cases clearly involve luck, some may find it less obvious what exactly the luck pertains to. An alternative interpretation of The Logical Bandit is that the protagonist is lucky that he guessed correctly, which was neither necessary nor particularly probable, since he could easily have guessed something else. Likewise, while it may be necessary that Fermat’s last theorem is true, it was neither necessary nor particularly probable that Fermat would believe that it is. However, Hales provides reasons for doubting that this ‘paraphrasing strategy’ will be successful (2016: p. 497). As an anonymous reviewer points out, there may be further reason to doubt the Fermat case, since Fermat may have been reliable in coming up with true theorems, even when he wasn’t able to construct a proof. However, this source of doubt could plausibly be remedied by stipulating that Fermat was not reliable at such non-rigorous conjecturing.

  8. 8.

    Stoutenberg appears to be accepting such a strong version of infallibilism in the main text on page 7 in his (2018); however, in the accompanying footnote 12, he appears to instead endorse the more traditional and less demanding version of infallibilism that makes evidential certainty a mere necessary condition for being in a position to know. In any case, his account of luck requires the stronger version in order to survive Hales’ counterexamples, which should be seen as a significant drawback.

  9. 9.

    For discussions making this clear, see e.g. Christensen (2010) and DiPaolo (2016). For my own preferred account of higher-order defeat, see Rasmussen et al. (2018), Skipper and Steglich-Petersen (forthcoming a), and Steglich-Petersen (forthcoming). For a recent collection of essays on higher-order evidence, see Skipper and Steglich-Petersen (forthcoming b).

  10. 10.

    For defences of conciliationism about higher-order evidence, see e.g. Feldman (2005), Christensen (2010) and Horowitz (2014).

  11. 11.

    For steadfast positions on higher-order evidence, see e.g. Kelly (2010), Lasonen-Aarnio (2014) and Titelbaum (2015).

  12. 12.

    While these verdicts about luck clearly rest on intuitions and not arguments, they are widely accepted in the literature on epistemic luck. See e.g. Pritchard (2005).


  1. Ballantyne, N. (2012). Luck and interests. Synthese, 185(3), 319–334.

  2. Baumann, P. (2014). No luck with knowledge? On a dogma of epistemology. Philosophy and Phenomenological Research, 89(3), 523–551.

  3. Broncano-Berrocal, F. (2016). Luck. Internet Encyclopedia of Philosophy.

  4. Christensen, D. (2010). Higher-order evidence. Philosophy and Phenomenological Research, 81(1), 185–215.

  5. Coffman, E. J. (2009). Does luck exclude control? Australasian Journal of Philosophy, 87(3), 499–504.

  6. DeRose, K. (1996). Knowledge, assertion, and lotteries. Australasian Journal of Philosophy, 74, 568–580.

  7. DiPaolo, J. (2016). Higher-order defeat is object-independent. Pacific Philosophical Quarterly.

  8. Dretske, F. (1970). Epistemic operators. Journal of Philosophy, 67, 1007–1023.

  9. Feldman, R. (2005). Respecting the evidence. Philosophical Perspectives, 19(1), 95–119.

  10. Hales, S. D. (2016). Why every theory of luck is wrong. Noûs, 50(3), 490–508.

  11. Horowitz, S. (2014). Epistemic akrasia. Noûs, 48(4), 718–744.

  12. Kelly, T. (2010). Peer disagreement and higher order evidence. In A. I. Goldman & D. Whitcomb (Eds.), Social epistemology: Essential readings (pp. 183–217). Oxford: Oxford University Press.

  13. Lackey, J. (2006). Pritchard’s epistemic luck. The Philosophical Quarterly, 56, 284–289.

  14. Lackey, J. (2008). What luck is not. Australasian Journal of Philosophy, 86(2), 255–267.

  15. Lasonen-Aarnio, M. (2014). Higher-order evidence and the limits of defeat. Philosophy and Phenomenological Research, 88(2), 314–345.

  16. Levy, N. (2011). Hard luck: How luck undermines free will and moral responsibility. Oxford: Oxford University Press.

  17. McKinnon, R. (2013). Getting luck properly under control. Metaphilosophy, 44(4), 496–511.

  18. Praëm, S. K., & Steglich-Petersen, A. (2015). Philosophical thought experiments as heuristics for theory discovery. Synthese, 192, 2827–2842.

  19. Pritchard, D. (2005). Epistemic luck. Oxford: Oxford University Press.

  20. Pritchard, D. (2014). The modal account of luck. Metaphilosophy, 45(4–5), 594–619.

  21. Rasmussen, M. S., Steglich-Petersen, A., & Bjerring, J. C. (2018). A higher-order approach to disagreement. Episteme, 15, 80–100.

  22. Rescher, N. (1995). Luck: The brilliant randomness of everyday life. Straus and Giroux: Farrar.

  23. Riggs, W. (2009). Luck, knowledge, and control. In D. Pritchard, A. Haddock, & A. Millar (Eds.), Epistemic value (pp. 204–221). Oxford: Oxford University Press.

  24. Skipper, M. & Steglich-Petersen, A. (forthcoming a). Group disagreement: A belief aggregation perspective. Synthese.

  25. Skipper, M. & Steglich-Petersen, A. (forthcoming b). Higher-order evidence: New essays. Oxford: Oxford University Press.

  26. Smith, M. (2010). What else justification could be. Noûs, 44(1), 10–31.

  27. Smith, M. (2016). Between probability and certainty: What justifies belief. Oxford: Oxford University Press.

  28. Steglich-Petersen, A. (2010). Luck as an epistemic notion. Synthese, 176(3), 361–377.

  29. Steglich-Petersen, A. (forthcoming). Higher-order defeat and doxastic resilience. In M. Skipper, & A. Steglich-Petersen (Eds.), Higher-order evidence: New essays. Oxford: Oxford University Press.

  30. Stoutenburg, G. (2015). The epistemic analysis of luck. Episteme, 12(3), 319–334.

  31. Stoutenburg, G. (2018). In defense of an epistemic probability account of luck. Synthese, 1–15.

  32. Titelbaum, M. (2015). Rationality’s fixed point (or: in defense of right reason). Oxford Studies in Epistemology, 5, 253–294.

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Correspondence to Asbjørn Steglich-Petersen.

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Steglich-Petersen, A. Does luck exclude knowledge or certainty?. Synthese (2018).

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  • Luck
  • Probability theory of luck
  • Knowledge
  • Epistemic probability