Uniqueness, Rationality, and the Norm of Belief


I argue that it is epistemically permissible to believe that P when it is epistemically rational to believe that P. Unlike previous defenses of this claim, this argument is not vulnerable to the claim that permissibility is being confused with excusability.

This is a preview of subscription content, log in to check access.


  1. 1.

    To give just one example, White (2005) moves freely between talk of what it is rational for one to believe and what it is epistemically permissible for one to believe, without further elaboration. This is typical. Even Goldman—arch reliabilist—was moved to revise his thinking in order to respect the apparent equivalence of rationality and permissibility (1986).

  2. 2.

    Which Cohen (1984) relies on in the course of presenting the ‘new evil demon’ argument against externalism, and which many epistemologists have subsequently relied on. I’ll discuss new evil demon style arguments in more detail later.

  3. 3.

    Whiting (2010, 2013), Littlejohn (2012).

  4. 4.

    Williamson (2000, 2013, forthcoming), Adler (2002), Sutton (2005, 2007), Littlejohn (2013, forthcoming).

  5. 5.

    In Hughes (forthcoming) I argued that we should reject the knowledge norm. This paper builds on that one by showing how similar considerations can be used to motivate a principled argument for the rationality norm.

  6. 6.

    The above notwithstanding, Cohen and Comesana briefly sketch a line of argument similar to the one I pursue in this article.

  7. 7.

    Various wordings of this principle can be found in the literature. I take this one from White (2005).

  8. 8.

    One can suspend judgement on P whilst having a high credence in it. To be clear, my claim is that do to that in this case would be too cautious.

  9. 9.

    The claim that rationality is necessary for permissibility is the contrapositive of II.

  10. 10.

    Given the standard assumption that knowledge entails rationality it is natural to think that knowledge normers are themselves committed to the truth of II. After all, if knowledge entails rationality, and you are obligated to only believe what you know, doesn’t it follow that you are obligated to only believe what it is rational for you to believe? And if so, isn’t II true? It turns out that the matter isn’t so straightforward. For one thing, the idea that knowledge entails rationality has recently been called into question (Lasonen-Aarnio 2010). But more importantly, knowledge normers are committed to saying that there are cases (like CAR) in which you are obligated to suspend judgement on P, even though it is irrational to do so. The upshot is that whilst they might want to agree that it is impermissible for you to believe that P when it is irrational for you to believe that P, they are not in a position to endorse II in full generality (i.e. as saying that for any doxastic attitude—suspension included—it is permissible to take that attitude just in case it is rational to take that attitude). Thanks to a referee for this journal for pointing out the need for clarification on this matter.

  11. 11.

    Williamson’s argument here is a development of the idea that we must draw a distinction between ‘primary’ and ‘secondary’ norms. That distinction was first drawn by DeRose (2002).

  12. 12.

    Lackey (2007) appeals to game cases when discussing applications of the primary/secondary norm distinction to theorising about the epistemic norms of assertion. She does so for a different purpose to mine, though. Lackey wants to argue that the primary/secondary norm distinction is a spurious one. I only want to argue that we are not prone to mistakenly conflate the manifestation of disposition to violate an obligation, O, with an actual violation of O.

  13. 13.

    As Cohen and Comesaña (forthcoming) point out, given the pervasiveness of misleading evidence, a theory that posits dilemmas in order to rescue the truth or knowledge norms will be committed to saying that each of us faces dilemmas of this kind on a regular basis, which seems even more odd a position to take. On a different note, Friedman (2013) argues against the traditional view that one suspends on P just in case one has considered the question of whether P and neither believes nor disbelieves that P. She argues that it is possible to have no attitude at all towards a proposition even after having considered the question of whether or not it is true. Even if Friedman right, however, it’s hard to see how that might help those who would reject DP. If each of the attitudes belief, suspension, and disbelief, is impermissible, then taking no attitude towards P would be the only permissible course of action, and would thereby be obligatory. Knowledge normers who reject DP wouldn’t be committed to the possibility of epistemic dilemmas in the conventional sense, then, but the view that there can be cases in which one is obligated to take no attitude towards a proposition is, it seems to me, just as odd as a view on which there are epistemic dilemmas. Moreover, there is a fairly strong sense in which normal agents will be unable to fulfil this would-be obligation. So this line of argument runs afoul of the ‘ought-implies-can’ principle.

  14. 14.

    See also Hughes (forthcoming).

  15. 15.

    Note that even if suspension is the appropriate attitude to take towards P, this is still action guiding. If I want water, and I suspend judgement on what locations it is available in my vicinity, then I can use this desire/doxastic attitude combination to motivate seeking out more evidence on the question of where there is water available. By contrast, if I am obligated, as per the rejection of DP, to have no attitude at all, then I will be obligated to be in a state of mind in which I cannot even do this. Relatedly, it should be clear that this argument will still apply even if we reject the tradition account of suspension of judgement and replace it with Friedman’s account.

  16. 16.

    This error theory is put forward by Williamson (2000, 2013, forthcoming), Sutton (2005, 2007), and Littlejohn (2012, forthcoming).

  17. 17.

    The distinction between rebutting and undercutting arguments is this: rebutting arguments are supposed to show that P is false. Undercutting arguments aren't supposed that P is false. Rather, they aim to undermine the putative evidential connection between a set of facts and the conclusion that is being drawn from them. (See Pollock 1986). I discussed the error theory in Hughes (forthcoming). I don't think I properly characterised it there, however. What I have said here better captures it.

  18. 18.

    Though of course I don't think we should agree with the error theorists about this. That's the point of my overall argument.

  19. 19.

    I don't mean to suggest here that one should always prefer, and seek, to be in a clear-cut case over a complex case. But equally one should not always prefer and seek to be in a complex case rather than a clear-cut case. One should go wherever the evidence leads.

  20. 20.

    See also Hughes (forthcoming).

  21. 21.

    This view is taken by Williams (1973), Railton (1994), Velleman (2000), Boghossian (2003), Shah (2003), and Shah and Velleman (2005), amongst others.


  1. Adler, J. (2002). Belief’s own ethics. Cambridge: MIT Press.

    Google Scholar 

  2. Boghossian, P. (2003). The normativity of content. Philosophical Issues, 13(1), 31–45.

    Article  Google Scholar 

  3. Cohen, S. (1984). Justification and truth. Philosophical Studies, 46(3), 279–295.

    Article  Google Scholar 

  4. Cohen, S. & Comesaña, J. (forthcoming). Being rational and being right. In J. Dutant & D. Dohrn (Eds.) The new evil demon. Oxford: Oxford University Press.

  5. DeRose, K. (2002). Assertion, knowledge, and context. Philosophical Review, 111(2), 167–203.

    Article  Google Scholar 

  6. Friedman, J. (2013). Suspended judgment. Philosophical Studies, 162(2), 165–181.

    Article  Google Scholar 

  7. Gibbons, J. (2013). The norm of belief. Oxford: Oxford University Press.

    Google Scholar 

  8. Hughes, N. (forthcoming). No excuses: Against the knowledge norm of belief. Thought: A Journal of Philosophy.

  9. Kelly, T. (2014). Evidence can be permissive. In M. Steup, J. Turri, & E. Sosa (Eds.), Contemporary debates in epistemology (2nd ed., pp. 298–313). Oxford: Blackwell.

    Google Scholar 

  10. Lackey, J. (2007). Norms of assertion. Nous, 41(4), 594–626.

    Article  Google Scholar 

  11. Lasonen-Aarnio, M. (2010). Unreasonable knowledge. Philosophical Perspectives, 24, 1–21.

    Article  Google Scholar 

  12. Littlejohn, C. (2012). Justification and the truth-connection. Cambridge: Cambridge University Press.

    Google Scholar 

  13. Littlejohn, C. (2013). The Russellian Retreat. Proceedings of the Aristotelian Society, 113(3), 293–320.

    Article  Google Scholar 

  14. Littlejohn, C. (forthcoming). A plea for epistemic excuses. In J. Dutant & F. Dorsch (Eds.), The new evil demon. Oxford: Oxford University Press.

  15. Lord, E. (2015). Acting for the right reasons, abilities, and obligations. In J. Hawthorne, & T’. Gendler Vellemen (Eds.), Oxford studies in metaethics (Vol. 10). Oxford: Oxford University Press.

  16. Moss, S. (2014). Epistemology formalized. Philosophical Review, 122, 1–43.

    Article  Google Scholar 

  17. Pollock, J. (1986). Contemporary theories of knowledge. Savage, MD: Rowman and Littlefield.

    Google Scholar 

  18. Railton, P. (1994). Truth, reason, and the regulation of belief. Philosophical Issues., 5, 71–93.

    Article  Google Scholar 

  19. Rosen, G. (2001). Nominalism, naturalism, epistemic relativism. Philosophical Perspectives, 15, 60–91.

    Google Scholar 

  20. Schoenfield, M. (2014). Permission to believe: Why permissivism is true and what it tells us about irrelevant influences on belief. Nous, 48(2), 263–277.

    Article  Google Scholar 

  21. Shah, N. (2003). How truth governs belief. Philosophical Review., 112(4), 447–482.

    Article  Google Scholar 

  22. Shah, N., & Velleman, D. (2005). Doxastic deliberation. Philosophical Review, 114(4), 497–534.

    Article  Google Scholar 

  23. Sutton, J. (2005). Stick to what you know. Nous, 39(3), 359–396.

    Article  Google Scholar 

  24. Sutton, J. (2007). Without justification. Cambridge, MA: MIT Press.

    Google Scholar 

  25. Velleman, D. (2000). On the aim of belief. In The possibility of practical reason. Oxford: Oxford University Press.

  26. White, R. (2005). Epistemic permissiveness. Philosophical Perspectives, 19(3), 445–459.

    Article  Google Scholar 

  27. Whiting, D. (2010). Does belief aim (only) at the truth? Pacific Philosophical Quarterly, 93, 279–300.

    Article  Google Scholar 

  28. Whiting, D. (2013). Nothing but the truth: On the aims and norms of belief. In T. Chan (Ed.), The aim of belief. Oxford: Oxford University Press.

    Google Scholar 

  29. Williams, B. (ed) (1973). Deciding to believe. In Problems of the self. Cambridge: Cambridge University Press.

  30. Williamson, T. (2000). Knowledge and its limits. New York: Oxford University Press.

    Google Scholar 

  31. Williamson, T. (2013). Response to Cohen, Comesaña, Goodman, Nagel, and Weatherson on Gettier cases in epistemic logic. Inquiry: An Interdisciplinary Journal of Philosophy, 56(1), 77–96.

    Article  Google Scholar 

  32. Williamson, T. (forthcoming). Justifications, excuses, and sceptical scenarios. In J. Dutant & D. Dohrn (eds.) The new evil demon, Oxford: Oxford University Press.

Download references


Thanks to Matthew McGrath, Herman Cappelen, Jessica Brown, Patrick Greenough, Torfinn Huvenes, Stewart Cohen, Clayton Littlejohn, and two anonymous referees for this journal for discussion and helpful feedback on earlier versions of this article.

Author information



Corresponding author

Correspondence to Nick Hughes.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Hughes, N. Uniqueness, Rationality, and the Norm of Belief. Erkenn 84, 57–75 (2019). https://doi.org/10.1007/s10670-017-9947-6

Download citation