Skip to main content
SpringerLink
Log in

Counterfactual Knowledge, Factivity, and the Overgeneration of Knowledge

  • Original Research
  • Published:
Erkenntnis Aims and scope Submit manuscript

Abstract

Antirealists who hold the knowability thesis, namely that all truths are knowable, have been put on the defensive by the Church–Fitch paradox of knowability. Rejecting the non-factivity of the concept of knowability used in that paradox, Edgington has adopted a factive notion of knowability, according to which only actual truths are knowable. She has used this new notion to reformulate the knowability thesis. The result has been argued to be immune against the Church–Fitch paradox, but it has encountered several other triviality objections. Schlöder in a forthcoming paper defends the general approach taken by Edgington, but amends it to save it in turn from the triviality objections. In this paper I will argue, first, that Schlöder’s justification for the factivity of his version of the concept of knowability is vulnerable to criticism, but I will also offer an improved justification that is in the same spirit as his. To the extent that some philosophers are right about our intuitive concept of knowability being a factive one, it is important to explore factive concepts of knowability that are made formally precise. I will subsequently argue that Schlöder’s version of the knowability thesis overgenerates knowledge or, in other words, it leads to attributions of knowledge where there is ignorance. This fits a general pattern for the research programme initiated by Edgington. This paper also contains preliminary investigations into the internal and logical structure of lines of inquiries, which raise interesting research questions.

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

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Notes

  1. Relatedly, Artemov and Protopopescu (2013) and Fischer (2013) have argued not for making knowability factive but for restricting the knowability thesis to certain classes of truths, namely so-called ‘stable’ and ‘uniform’ truths, respectively.

  2. One can show similarly that, if \(\Diamond K\phi \) is supposed to be necessarily factive, then \(\Box \phi \) follows from it.

  3. The following example was given by Lorenz Demey and roughly the same example was given by an anonymous reviewer.

  4. This example is based on (Edgington 1985, p. 565).

  5. I am assuming here that it is meant that the ‘without changing the truth value of q’ bit is within the scope of the knowledge that has been imparted by the course of inquiry i.

  6. Julian J. Schlöder suggested an ‘algebra of lines of inquiry’ during discussion of his work in Leuven on 22 February 2019.

  7. By the way, it could also have happened that both vessels go north and that they detect the presence of each other (although that is not always the case). But even if there were a detection of the other vessel, it is not easy to find out about the detection technology on board of the other ship. There remains de re ignorance about the other line of inquiry.

References

  • Artemov, S., & Protopopescu, T. (2013). Discovering knowability: A semantic analysis. Synthese, 190(16), 3349–3376.

    Article  Google Scholar 

  • Brogaard, B., & Salerno, J. (2006). Knowability and a modal closure principle. American Philosophical Quarterly, 43(3), 261–270.

    Google Scholar 

  • Dummett, M. A. E. (1991). The logical basis of metaphysics. Cambridge: Harvard University Press.

    Google Scholar 

  • Edgington, D. (1985). The paradox of knowability. Mind, 94(376), 557–568.

    Article  Google Scholar 

  • Edgington, D. (2010). Possible knowledge of unknown truth. Synthese, 173(1), 41–52.

    Article  Google Scholar 

  • Fara, M. (2010). Knowability and the capacity to know. Synthese, 173(1), 53–73.

    Article  Google Scholar 

  • Fischer, M. (2013). Some remarks on restricting the knowability principle. Synthese, 190(1), 63–88.

    Article  Google Scholar 

  • Fitch, F. B. (1963). A logical analysis of some value concepts. Journal of Symbolic Logic, 28(2), 135–142.

    Article  Google Scholar 

  • Fuhrmann, A. (2014). Knowability as potential knowledge. Synthese, 191(7), 1627–1648.

    Article  Google Scholar 

  • Hart, W. D. (1979). The epistemology of abstract objects: Access and inference. Proceedings of the Aristotelian Society, 53, 153–165.

    Google Scholar 

  • Hart, W. D., & McGinn, C. (1976). Knowledge and necessity. Journal of Philosophical Logic, 5, 205–208.

    Article  Google Scholar 

  • Heylen, J. (2020). Factive knowability and the problem of possible omniscience. Philosophical Studies, 177(1), 65–87.

    Article  Google Scholar 

  • Hintikka, J. (1962). Knowledge and belief. Ithaca: Cornell University Press.

    Google Scholar 

  • Kaplan, D. (1989). Demonstratives. In J. Almog, A. J. Perry, & H. Wettstein (Eds.), Themes from kaplan (pp. 481–563). Oxford: Oxford University Press.

    Google Scholar 

  • Kripke, S. A. (1963). Semantical considerations on modal logic. Acta Philosophica Fennica, 16(1963), 83–94.

    Google Scholar 

  • Kvanvig, J. (1995). The knowability paradox and the prospects for anti-realism. Noûs, 29(4), 481–500.

    Article  Google Scholar 

  • Lewis, D. K. (1973). Counterfactuals. Hoboken: Blackwell.

    Google Scholar 

  • Rabinowicz, W., & Segerberg, K. (1994). Actual truth, possible knowledge. Topoi, 13(2), 101–115.

    Article  Google Scholar 

  • Schlöder, J. J. (2019). Counterfactual knowability revisited. Synthese, 1–15

  • Spencer, J. (2017). Able to do the impossible. Mind, 126(502), 466–497.

    Article  Google Scholar 

  • Tennant, N. (1997). The taming of the true. Oxford: Oxford University Press.

    Google Scholar 

  • Williamson, T. (1987). On the paradox of knowability. Mind, 96(382), 256–261.

    Article  Google Scholar 

Download references

Acknowledgements

I am particularly grateful to Julian J. Schlöder, who presented his work in Leuven on 22 February 2019 and with whom I could discuss his work before and after the presentation. Part of my paper has been presented at the XX Jornadas Rolando Chuaqui Kettlun (Santiago de Chile, 27 August 2019–30 August 2019). I am grateful to the organizers for their invitation and I would like to thank the audience for their feedback. In addition, I would also like to thank Felipe Morales Carbonell, Lars Arthur Tump and Lorenz Demey for their feedback on this paper. Special thanks goes to Lorenz Demey for discussion of Sect. 3. Last but not least, I am thankful to two anonymous reviewers for their very helpful reviews.

Author information

Authors and Affiliations

  1. Centre for Logic and Philosophy of Science, Institute of Philosophy, KU Leuven, Andreas Vesaliusstraat 2, 3000, Leuven, Belgium

    Jan Heylen

Authors
  1. Jan Heylen
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Jan Heylen.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Research for this article was generously sponsored by the Fund for Scientific Research – Flanders (Project Grant G088219N), which is gratefully acknowledged.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Heylen, J. Counterfactual Knowledge, Factivity, and the Overgeneration of Knowledge. Erkenn 87, 2243–2263 (2022). https://doi.org/10.1007/s10670-020-00300-w

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10670-020-00300-w

Search

Navigation