Consistency and evidence


Williamson (2000) appeals to considerations about when it is natural to say that a hypothesis is consistent with one’s evidence in order to motivate the claim that all and only knowledge is evidence. It is argued here that the relevant considerations do not support this claim, and in fact conflict with it.

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


  1. 1.

    E=K has attracted its fair share of critics. Here’s a sample: Brueckner (2005), Silins (2005), Dodd (2007), Conee and Feldman (2008), Kelly (2008), Neta (2008), Goldman (2009), Comesana and Kantin (2010), Dancy (2011). Comesana and Kantin (2010) argue that if E=K is incompatible with the existence of a certain kind of Gettier cases. Since these Gettier cases exist, they conclude that E=K is false. My argument will also involve Gettier cases, but in a different way.

  2. 2.

    As an aside, it is worth additionally noting that if this is correct it also serves to refute the argument on its deductive interpretation (uncharitable though it is). For if we can show that considerations about when it is natural to say that a hypothesis is consistent or inconsistent with one’s evidence positively support the claim that the contents of some non-K JTBs are evidence, then we will have shown a fortiori that there are counterexamples to the claim that, for the content of every belief that falls short of knowledge, it is natural to say that the negation of that content is consistent with one’s evidence.

  3. 3.

    This point has been made by Dodd (2007), Weatherson (ms), and McGlynn (ms).

  4. 4.

    McGlynn (ms) also makes this observation.

  5. 5.

    Pritchard (forthcoming) describes this as one of the ‘master intuitions’ driving Gettier cases.

  6. 6.

    Plausibly, the case is much better understood as analogous to a lottery case—a case where you believe solely on the basis of the probabilities involved that your lottery ticket is a loser. This raises interesting issues in itself, since a number of epistemologists (e.g. Smithies 2012; Smith 2010; Sutton 2007, amongst others) have argues that you not only cannot know that your ticket has lost solely on the basis of the probabilities involved, but you cannot even justifiably outright believe that it has. In that case, we might wonder if Williamson’s description of the case as involving a justified belief is correct. Regrettably, I cannot go into these issues here. But the important thing to note is that the case bears little resemblance to a typical Gettier case.

  7. 7.

    The phrase ‘Gettier case’ is sometimes used to refer to any case of a justified true belief that is not knowledge, irrespective of the specific features of the believers epistemic situation. I do not use the phrase in that way. I’m taking ‘typical Gettier case’ to refer to cases that have the features outlined above. If the reader is unhappy with this, they should mentally replace the phrase ‘not a Gettier case’ with ‘not a case where the subject is lucky that they truly belief that p, nor in a position to know that they don’t know that p, nor in an abnormal epistemic environment such that were they aware of the abnormality, they would not longer be justified in believing that p’.

  8. 8.

    Of course, it might be argued that a black ball disguised as a red ball simply is a red ball. I ask the reader to put this concern aside. The case could be easily amended to get around the worry.

  9. 9.

    Littlejohn (2012) argues that Goldman’s fake barns case, which is structurally similar to mine, causes problems for E=K. Littlejohn’s argument, however, trades directly on the intuition that the driver has the same evidence when the are driving in real-barn country and fake-barn country, rather than engaging with Williamson’s consistency argument.

  10. 10.

    In my adaptation of Williamson’s case, the subject has a veridical experience, but fails to know because they are in an environmental where they could easily have had a non-veridical experience. Hence their belief is ‘environmentally’ lucky. By contrast, some Gettier cases involve subjects having non-veridical experiences, but forming a belief that is, by a stroke of luck, in fact true. Chisholm’s (1966) sheep in a field case is one such case. In these cases the luck ‘intervenes’ to turn the subject’s would-be-false belief into a true belief. It is less clear to me that the consistency argument fails to deliver the verdict Williamson needs in such cases. See Pritchard (2010) for more on the distinction between environmental and intervening luck.


  1. Brueckner, A. (2005). Knowledge, evidence, and skepticism according to Williamson. Philosophy and Phenomenological Research, 70(2), 436–443.

    Article  Google Scholar 

  2. Chisholm, R. (1966). Theory of knowledge. Englewood Cliffs, NJ: Prentice Hall.

    Google Scholar 

  3. Comesana, J., & Kantin, H. (2010). Is evidence knowledge? Philosophy and Phenomenological Research, 80, 447–454.

    Article  Google Scholar 

  4. Conee, E., & Feldman, R. (2008). Evidence. In Q. Smith (Ed.), Epistemology: New essays (pp. 83–104). New York: Oxford University Press.

    Google Scholar 

  5. Dancy, J. (2011). Acting in ignorance. Frontiers of Philosophy in China, 6(3), 345–357.

    Article  Google Scholar 

  6. Dodd, D. (2007). Why Williamson should be a sceptic. The Philosophical Quarterly, 57, 635–649.

    Article  Google Scholar 

  7. Goldman, A. (2009). Williamson on knowledge and evidence. In P. Greenough & D. Pritchard (Eds.), Williamson on knowledge (pp. 73–92). New York: Oxford University Press.

    Google Scholar 

  8. Joyce, J. (2004). Williamson on evidence and knowledge. Analytic Philosophy, 45(4), 296–305.

    Google Scholar 

  9. Kelly, T. (2008). Evidence: Fundamental concepts and the phenomenal conception. Philosophy Compass, 3(5), 933–955.

    Google Scholar 

  10. Littlejohn, C. (2012). Evidence and knowledge. Erkenntnis, 74, 241–262.

    Article  Google Scholar 

  11. McGlynn, A. (manuscript). Knowledge first?

  12. Neta, R. (2008). What evidence do you have? British Journal for Philosophy of Science, 59, 89–119.

    Google Scholar 

  13. Pritchard, D. (2010). Knowledge and understanding. In D. H. Pritchard, A. Millar, & A. Haddock (Eds.), The nature and value of knowledge: Three investigations. Oxford: Oxford University Press.

    Google Scholar 

  14. Pritchard, D. (2012). Anti-luck virtue epistemology. Journal of Philosophy, 109, 247–279.

    Google Scholar 

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

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

    Article  Google Scholar 

  17. Smithies, D. (2012). The normative role of knowledge. Nous, 46(2), 265–288.

    Article  Google Scholar 

  18. Weatherson, B. (manuscript). E≠K.

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

    Google Scholar 

Download references


Thanks to Herman Cappelen, Jessica Brown, Aidan McGlynn, Robin McKenna, Sebastian Becker, Andrew Peet, Bruno Jacinto, Michael Hannon, and audiences at the Arche Epistemology Seminar, the University of Edinburgh Epistemology Graduate Conference, and the University of Manchester Open Minds VIII Conference, for helpful comments and feedback on earlier versions of this paper.

Author information



Corresponding author

Correspondence to Nick Hughes.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Hughes, N. Consistency and evidence. Philos Stud 169, 333–338 (2014).

Download citation


  • Knowledge
  • Evidence
  • E=K
  • Timothy Williamson
  • Gettier