Abstract
Starting with Jaakko Hintikka’s seminal work, epistemic logic has now grown up to a huge academic industry. When we look back to its history, however, there is a practical paradox. While Hintikka’s original purpose was to facilitate epistemological discussion, most subsequent work of epistemic logic has been done outside of philosophy, and has been ignored by most mainstream epistemologists. At the current point, one might naturally wonder, does epistemic logic still have something to do with epistemology? Along with Hintikka and a growing number of formal epistemologists, we believe the answer is “yes”. Contemporary epistemology has largely focused on the goal of providing an analysis of knowledge and an answer to skepticism. To avoid skepticism, many epistemologists prefer to define knowledge in terms of evidence and relevant alternatives. A typical saying is that “in order to know that p, one only needs evidence to eliminate all relevant alternatives, rather than all alternatives”. We see such a project as perfectly congenial to the spirit of Hintikka’s epistemic logic. In this paper, we propose an epistemic logic (EREL) to deal with evidence and relevant alternatives explicitly, and extend EREL to its dynamic version (PARL) to investigate how different notions of knowledge behavior with the decrease and increase of relevant alternatives. To illustrate its philosophical application, we provide a new formalization of the so called factivity problem of epistemic contextualism. We conclude with some remarks on further developments of our framework.
This is a preview of subscription content, log in via an institution.
Notes
- 1.
Note that, Hintikka originally interprets epistemic formulas in model sets ([24], pp. 40–41). Roughly speaking, model sets are sets of formulas which partially describe possible states of affairs. Therefore, Hintikka’s semantics of epistemic logic are different from nowadays routine. Thank Professor Gabriel Sandu to remind us this.
- 2.
According to Timothy Williamson, if one wants to be fully realistic, “knowledge implies truth” might be the only valid principle of knowledge (personal communication in 2009).
- 3.
As far as we know, such a link-cutting dynamics was first introduced by van Benthem and Liu in the literature of preference upgrade [44].
- 4.
As proved by Wang Yanjing, without axiom P5, one need the rule of equivalence replacement (RE: from \(\vdash \psi \leftrightarrow \chi \), derive \(\vdash \varphi \leftrightarrow \varphi (\psi /\chi )\)) to get a complete axiomatization of PAL [46].
- 5.
Why not denying (c)? According to the first author, such an option, if not more, is equally plausible. It’s nature to think that, if one knows that p but does not know that q, then it is epistemically possible for her that p and not q, even if it is not logically possible.
- 6.
We only prove \(CS(O\wedge \lnot H)=CS(O)\). \(CS(O\vee \lnot H)=CS(\lnot H)\) can be proved similarly. For any \(P\in CS(O)\), according to the definition of CS, O entails \(\lnot P\). Since O is clearly entailed by \(O\wedge \lnot H\), so \(O\wedge \lnot H\) also entails \(\lnot P\). By definition of CS again, \(P\in CS(O\wedge \lnot H)\). On the other hand, for any \(P\in CS(O\wedge \lnot H)\), according to the definition of CS, \(O\wedge \lnot H\) entails \(\lnot P\). Since O entails \(\lnot H\), O also entails \(O\wedge \lnot H\), and thus entails \(\lnot P\). Again by definition of CS, \(P\in CS(O)\).
- 7.
One could easily generalize P and \(K_{s}\) to account for relevant alternatives and knowledge attributions under multiple contexts, e.g., let \(P^{c}\varphi \) represents “\(\varphi \) is true at all relevant alternatives in context c”, and \(K^{c}_{s}\varphi \) represents “s know that \(\varphi \) in context c”. In that case, our \(P\varphi \) and \(K_{s}\varphi \) can be seen as abbreviation of \(P^{c}\varphi \) and \(K^{c}_{s}\varphi \) for some fixed context c.
References
Barke A (2004) Epistemic contextualism. Erkenntnis 61:353–373
Baumann P (2008) Contextualism and the factivity problem. Philos Phenomenol Res 76(3):580–602
Black T (2003) The relevant alternatives theory and missed clues. Aust J Philos 81(1):96–106
Blome-Tillmann M (2009) Knowledge and presuppositions. Mind 118(470):241–294
Catterson T (2008) The semantic turn in epistemology: a critical examination of hinttika’s logic of knowledge. In: Hendricks VF, Pritchard D (eds) New Waves Epistemol. Palgrave Macmillan, Basingstoke, pp 137–163
Cohen S (1988) How to be a fallibilist. Philos Perspect 2:91–123
Cohen S (1999) Contextualism, skepticism, and the structure of reasons. supplement: philosophical perspectives, 13. Epistemology 33:57–89
Cohen S (2002) Basic knowledge and the problem of easy knowledge. Philos Phenomenol Res 65(2):309–329
Collier K (1987) Hintikka’s epistemic logic. In: Bogdan RJ (ed) Jaakko Hintikka. D. Reidel Publishing Company, Dordrecht, Holland, pp 181–198
de Bruin B (2008) Epistemic logic and epistemology. In: Hendricks VF, Pritchard D (eds) New Waves Epistemol. Palgrave Macmillan, Basingstoke, pp 106–136
DeRose K (1995) Solving the skeptical problem. Philos Rev 104(1):1–52
Dretske F (1970) Epistemic operators. J Philos 67:1007–1023
Dretske F (1981) The pragmatic dimension of knowledge. Philos Stud 40:363–378
Dretske F (2004) Externalism and modest contextualism. Erkenntnis 61(2–3):173–186
Fagin R, Halpern JY, Moses Y, Vardi MY (1995) Reasoning about knowledge. MIT Press, Cambridge, MA
Freitag W (2011) Epistemic contextualism and the knowability problem. Acta Anal 26(3):273–284
Gargov G, Passy S, Tinchev T (1987) Modal environment for boolean speculations. In: Skordev DG (ed) Mathematical logic and its applications, US. Springer, pp 253–263
Gerbrandy J, Groeneveld W (1997) Reasoning about information change. J Logic Lang Inf 6:147–169
Goldman AI (1976) Discrimination and perceptual knowledge. J Philos 73(20):771–791
Hawthorne J (2005) The case for closure. In: Steup M, Sosa E (eds) Contemporary debates in epistemology, 1st edn. Blackwell Publishing, Malden, MA, USA, pp 26–43
Heller M (1999) Relevant alternatives and closure. Aust J Philos 77(2):196–208
Hendricks VF (2005) Mainstream and formal epistemology. Cambridge University Press, New York, USA
Hendricks VF, Symons J (2006) Where’s the bridge? epistemology and epistemic logics. Philos Stud 128:137–167
Hintikka J (1962) Knowledge and belief: an introduction to the logic of the two notions. Cornell University Press
Hintikka J (1986) Reasoning about knowledge in philosophy: the paradigm of epistemic logic. In: Halpern JY (ed) Reasoning about knowledge: proceedings of the 1986 conference, Los Altos, CA. Morgan Kaufmann Publishers, pp 63–80
Hintikka J (2003) A second generation epistemic logic and its general significance. In: Hendricks VF, Jorgensen KF, Pedersen SA (eds) Knowledge contributors. Springer, Netherlands, Springer Netherlands, pp 33–55
Hocutt MO (1972) Is epistemic logic possible? Notre Dame J Form Logic 13(4):433–453
Holliday W (2012) Knowing what follows: epistemic closure and epistemic logic. PhD thesis, Standford University
Holliday W (2015) Epistemic closure and epistemic logic i: relevant alternatives and subjunctivism. J Philos Log 44(1):1–62
Holliday W (2016) Epistemic logic and epistemology. In: Hansson S, Hendricks V (eds) Handbook of formal philosophy. Springer
Kripke SA (2011) Nozick on knowledge. In: Collected papers vol I. Oxford University Press
Lewis D (1996) Elusive knowledge. Aust J Philos 74(4):549–567
Liu F (2011) Reasoning about preference dynamics, 1 edn. Springer, Netherlands
McLane E (1979) On the possibility of epistemic logic. Notre Dame J Form Log 20(3):559–574
Meyer J-JC, van der Hoek W (1995) Epistemic logic for AI and computer science. Cambridge University Press, Cambridge, England
Plaza J (1989) Logics of public communications. In: Proceedings of the 4th international symposium on methodologies for intelligent systems, pp 201–216
Roelofsen F (2007) Distributed knowledge. J Appl Non-Class Log 17(2):255–273
Schaffer J (2001) Knowledge, relevant alternatives and missed clues. Analysis 61(271):202–208
Sherman B, Harman G (2011) Knowledge and assumptions. Philos Stud 156(1):131–140
Stine GC (1976) Skepticism, relevant alternatives, and deductive closure. Philos Stud 29:249–261
van Benthem J (2006) Epistemic logic and epistemology: the state of their affairs. Philos Stud 128:49–76
van Benthem J (2014) Logical dynamics of information and interaction. Cambridge University Press, New York, NY, USA
van Benthem J, Ghosh S, Verbrugge R (eds) (2015) Models for stratigical reasoning. Springer, Nertherland
van Benthem J, Liu F (2007) Dynamic logic of preference upgrade. J Appl Non-Class Log 17(2):157–182
van Ditmarsch H, van der Hoek W, Kooi B (2007) Dynamic epistemic logic. Springer, New York LLC
Wang Y (2011) On axiomatizations of pal. In: van Ditmarsch H, Lang J, Ju S (eds) Logic, rationality, and interaction, vol 6953. Lecture notes in computer science. Springer, Heidelberg, pp 314–327
Williamson T (2013) Gettier cases in epistemic logic. Inquiry 56(1):1–14
Xu Z (2012) Knowledge, evidence and relevant alternatives—a logical dynamical approach. PhD thesis, Peking University
Xu Z (2016) Philosophical criticism to epistemic logic. Manuscript
Yap A (2014) Idealization, epistemic logic, and epistemology. Synthese 191(14):3351–3366
Acknowledgements
The work is supported by the Chinese National Social Science Fund (12AZX008; 12AZD072), the Ministry of Education Humanities and Social Sciences Youth Project (15YJC72040001), and Sichuan University (skzx2015-sb05; skqy201645). Thank Professor Gabriel Sandu for helpful and detailed comments.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2018 Springer International Publishing AG
About this chapter
Cite this chapter
Xu, Z., Chen, B. (2018). Epistemic Logic with Evidence and Relevant Alternatives. In: van Ditmarsch, H., Sandu, G. (eds) Jaakko Hintikka on Knowledge and Game-Theoretical Semantics. Outstanding Contributions to Logic, vol 12. Springer, Cham. https://doi.org/10.1007/978-3-319-62864-6_22
Download citation
DOI: https://doi.org/10.1007/978-3-319-62864-6_22
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-62863-9
Online ISBN: 978-3-319-62864-6
eBook Packages: Religion and PhilosophyPhilosophy and Religion (R0)