A Defence of the Principle of Information Closure against the Sceptical Objection

  • Luciano Floridi
Part of the The Philosophy of Science in a European Perspective book series (PSEP, volume 4)


The topic of this paper may be introduced by fast zooming in and out of the philosophy of information. In recent years, philosophical interest in the nature of information has been increasing steadily. This has led to a focus on semantic information, and then on the logic of being informed, which has attracted analyses concentrating both on the statal sense in which S holds the information that p (this is what I mean by logic of being informed in the rest of this article) and on the actional sense in which S becomes informed that p. One of the consequences of the logic debate has been a renewed epistemological interest in the principle of information closure (henceforth PIC), which finally has motivated a revival of a sceptical objection against its tenability first made popular by Dretske. This is the topic of the paper, in which I seek to defend PIC against the sceptical objection. If I am successful, this means – and we are now zooming out – that the plausibility of PIC is not undermined by the sceptical objection, and therefore that a major epistemological argument against the formalization of the logic of being informed based on the axiom of distribution in modal logic is removed. But since the axiom of distribution discriminates between normal and non-normal modal logics, this means that a potentially good reason to look for a formalization of the logic of being informed among the non-normal modal logics, which reject the axiom, is also removed. And this in turn means that a formalization of the logic of being informed in terms of the normal modal logic B (also known as KTB) is still very plausible, at least insofar as this specific obstacle is concerned. In short, I shall argue that the sceptical objection against PIC fails, so it is not a good reason to abandon the normal modal logic B as a good formalization of the logic of being informed.


Modal Logic Factual Information Information Logic Sceptical Argument Normal Modal Logic 
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. Adams, F., 2011, “Information and Knowledge À La Floridi”, in P. Allo (Ed.), Putting Information First: Luciano Floridi and the Philosophy of Information. Oxford: Wiley-Blackwell, pp. 84-96.CrossRefGoogle Scholar
  2. Adams, F., Barker, J., and Figurelli, J. (forthcoming), “Towards Closure on Closure”, in: Synthese, pp. 1-18.Google Scholar
  3. Allo, P., 2011, “The Logic of ‘Being Informed’ Revisited and Revised”, in: Philosophical Studies, 153, 3, pp. 417-434.Google Scholar
  4. Barwise, J. and Seligman, J., 1997, Information Flow: The Logic of Distributed Systems. Cambridge: Cambridge University Press.CrossRefGoogle Scholar
  5. Baumann, P., 2006, “Information, Closure, and Knowledge: On Jäger’s Objection to Dretske”, in: Erkenntnis, 64, 3, pp. 403-408.Google Scholar
  6. Cocchiarella, N. B. and Freund, M. A., 2008, Modal Logic: An Introduction to Its Syntax and Semantics. New York–Oxford: Oxford University Press.Google Scholar
  7. D’Agostino, M. and Floridi, L., 2009, “The Enduring Scandal of Deduction. Is Propositional Logic Really Uninformative?”, in: Synthese, 167, 2, pp. 271-315.Google Scholar
  8. Dretske, F., 1981, Knowledge and the Flow of Information. Oxford: Blackwell.Google Scholar
  9. Dretske, F., 1999, Knowledge and the Flow of Information. Stanford, CA: CSLI Publications.Google Scholar
  10. Dretske, F., 2006, “Information and Closure”, in: Erkenntnis, 64, 3, pp. 409-413.Google Scholar
  11. Floridi, L., 2004, The Blackwell Guide to the Philosophy of Computing and Information. Oxford: Blackwell.CrossRefGoogle Scholar
  12. Floridi, L., 2006, “The Logic of Being Informed”, in: Logique et Analyse, 49, 196, pp. 433-460.Google Scholar
  13. Floridi, L., 2010, “Information, Possible Worlds, and the Cooptation of Scepticism”, in: Synthese 175, pp. 63-88.CrossRefGoogle Scholar
  14. Floridi, L., 2011a, “Semantic Conceptions of Information”, in E. N. Zalta (Ed.), The Stanford Encyclopedia of Philosophy. Spring Edition.Google Scholar
  15. Floridi, L., 2011b, The Philosophy of Information. Oxford: Oxford University Press.CrossRefGoogle Scholar
  16. Hintikka, J., 1962, Knowledge and Belief: An Introduction to the Logic of the Two Notions. Ithaca: Cornell University Press.Google Scholar
  17. Hughes, G. E. and Cresswell, M. J., 1984, A Companion to Modal Logic. London: Methuen.Google Scholar
  18. Jäger, C., 2004, “Skepticism, Information, and Closure: Dretske’s Theory of Knowledge”, in: Erkenntnis 61, 2-3, pp. 187-201.Google Scholar
  19. Kerr, E. T. and Pritchard, D. (forthcoming), “Skepticism and Information”, in: H. Demir (Ed.), Luciano Floridi’s Philosophy of Technology. New York: Sprin­ger.Google Scholar
  20. Luper, S., 2006, “Dretske on Knowledge Closure”, in: Australasian Journal of Philosophy 84, 3, pp. 379-394.Google Scholar
  21. Luper, S., 2010, “The Epistemic Closure Principle”, in: E. N. Zalta (Ed.), Stanford Encyclopedia of Philosophy.Google Scholar
  22. Nozick, R., 1981, Philosophical Explanations. Oxford: Clarendon Press.Google Scholar
  23. Schoenbaumsfeld, G. (submitted-a), “Mcdowellian Neo-Mooreanism?”Google Scholar
  24. Schoenbaumsfeld, G. (submitted-b), “Meaning and Conversational Impropriety in Sceptical Contexts”.Google Scholar
  25. Shackel, N., 2006, “Shutting Dretske’s Door”, in: Erkenntnis 64, 3, pp. 393-401.Google Scholar
  26. White, J. L., 1991, “Knowledge and Deductive Closure”, Synthese 86, 3, pp. 409-423.CrossRefGoogle Scholar

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© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  1. 1.Department of PhilosophyUniversity of HertfordshireHatfield, HertfordshireUK

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