Philosophical Studies

, Volume 174, Issue 4, pp 1039–1046 | Cite as

On Sharon and Spectre’s argument against closure

  • Juan ComesañaEmail author


Sharon and Spectre give the best argument against closure that I know of, and they are to be commended for bringing clarity to a discussion often enmeshed in obscurity. Nevertheless, I think that their argument proves less than they advertise.

Sharon and Spectre’s ultimate target is the following closure principle, taken from Williamson (2000) via Hawthorne (2005):

(CP) Necessarily, if S knows p, competently deduces q from p, and thereby comes to believe q, while retaining knowledge of p throughout, then S knows q.

Crucial to their argument against CP is another closure principle about evidence (I omit qualifications that won’t matter for our purposes):

(CE) Necessarily, if e is evidence for p for S and p entails q, then e is evidence for q for S.

Sharon and Spectre’s master argument is the following:
  1. 1.

    CE is false.

  2. 2.

    If CE is false, then CP is false.


  3. 3.

    CP is false.

I have doubts about both premises of this argument. Let’s start with the first premise.



Rational Confidence Alternative Conception Atomic Proposition Gettier Case Contingent Truth 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. Cohen, S. (2010). Bootstrapping, defeasible reasoning and a priori justification. Philosophical Perspectives, 24(1), 141–159.CrossRefGoogle Scholar
  2. Comesaña, J. (2013a). There is no immedaite justification. In Steup, Turri & Sosa (Eds.), Contemporary Debates in Epistemology (2nd ed.). Wiley-Blackwell.Google Scholar
  3. Comesaña, J. (2013b). Reply to Pryor. In Steup, Turri & Sosa (Eds.), Contemporary Debates in Epistemology (2nd ed.). Wiley-Blackwell.Google Scholar
  4. Comesaña, J., & Sartorio, C. (2014). Difference-making in epistemology, Noûs, 48(2), 368–387.Google Scholar
  5. Dretske, F. (2005). Is knowledge closed under known entailment? In Steup & Sosa (2005).Google Scholar
  6. Hawthorne, J. (2005). The case against closure. In Steup & Sosa (2005).Google Scholar
  7. Hempel, C. (1965). Aspects of scientific explanation. New York: Free Press.Google Scholar
  8. Pryor, J. (2013). Reply to Comesaña. In Steup, Turri & Sosa (Eds.).Google Scholar
  9. Steup, M., & Sosa, E. (Eds.). (2005). Contemporary debates in epistemology. London: Blackwell.Google Scholar
  10. Steup, M., Turri, J., & Sosa, E. (Eds.). (2013). Contemporary debates in epistemology (2nd ed.). Blackwell.Google Scholar
  11. van Fraassen, B. (1984). Belief and the will. Journal of Philosophy, 81, 235–256.CrossRefGoogle Scholar
  12. Vogel, J. (forthcoming). E and Not-H. In Dylan Dodd & Elia Zardini (Eds.), Scepticism and Percetual Justification, Oxford University Press.Google Scholar
  13. Wedgwood, R. (2012). A priori bootstrapping. In A Casullo & J. Thurow (Eds.), The a priori in philosophy, Oxford University Press, Oxford.Google Scholar
  14. Williamson, T. (2000). Knowledge and its limits. Oxford: Oxford University Press.Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  1. 1.TucsonUSA

Personalised recommendations