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Defeasible Conditionalization

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Abstract

The applicability of Bayesian conditionalization in setting one’s posterior probability for a proposition, α, is limited to cases where the value of a corresponding prior probability, PPRI(α|∧E), is available, where ∧E represents one’s complete body of evidence. In order to extend probability updating to cases where the prior probabilities needed for Bayesian conditionalization are unavailable, I introduce an inference schema, defeasible conditionalization, which allows one to update one’s personal probability in a proposition by conditioning on a proposition that represents a proper subset of one’s complete body of evidence. While defeasible conditionalization has wider applicability than standard Bayesian conditionalization (since it may be used when the value of a relevant prior probability, PPRI(α|∧E), is unavailable), there are circumstances under which some instances of defeasible conditionalization are unreasonable. To address this difficulty, I outline the conditions under which instances of defeasible conditionalization are defeated. To conclude the article, I suggest that the prescriptions of direct inference and statistical induction can be encoded within the proposed system of probability updating, by the selection of intuitively reasonable prior probabilities.

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References

  1. Bacchus, F. (1990). Representing and reasoning with probabilistic knowledge. Cambridge: MIT Press.

    Google Scholar 

  2. Bacchus, F., Grove, A., Halpern, J., & Koller, D. (1996). From statistical knowledge bases to degrees of belief. Artificial Intelligence, 87, 75–143.

    Article  Google Scholar 

  3. Carnap, R. (1962). Logical foundations of probability (2nd ed.). Chicago: University of Chicago Press.

    Google Scholar 

  4. Chisholm, R. (1957). Perceiving. Ithaca: Cornell University Press.

    Google Scholar 

  5. Good, I. (1962). Subjective probability as the measure of a non measurable set. In E. Nagel, P. Suppes, & A. Tarski (Eds.), Logic, methodology and the philosophy of science (pp. 319–329). Stanford: Stanford University Press.

    Google Scholar 

  6. Halpern, J. (2003). Reasoning about uncertainty. Cambridge: MIT Press.

    Google Scholar 

  7. Hart, H. (1948). The ascription of responsibility and rights. Proceedings of the Aristotelian Society.

  8. Hempel, C. (1968). Lawlikeness and maximal specificity in probabilistic explanation. Philosophy of Science, 35(2), 116–133.

    Article  Google Scholar 

  9. Horty, J. (2002). Skepticism and floating conclusions. Artificial Intelligence, 135, 55–72.

    Article  Google Scholar 

  10. Horty, J. (2007). Defaults with priorities. Journal of Philosophical Logic, 36, 367–413.

    Article  Google Scholar 

  11. Howson, C., & Urbach, P. (2006). Scientific reasoning: the Bayesian approach (3rd ed.). Chicago: Open Court Publishing.

    Google Scholar 

  12. Jaynes, E. (1968). Prior probabilities. IEEE Transactions On Systems Science and Cybernetics, 4(3), 227–241.

    Article  Google Scholar 

  13. Jeffrey, R. (1983). The logic of decision (2nd ed.). Chicago: The University of Chicago Press.

    Google Scholar 

  14. Kaplan, M. (1983). Decision theory as philosophy. Philosophy of Science, 50, 549–557.

    Article  Google Scholar 

  15. Kaplan, M. (2010). In defense of modest probabilism. Synthese, 176, 41–55.

    Article  Google Scholar 

  16. Keynes, J. (1921). A treatise on probability. London: Macmillan and Company.

    Google Scholar 

  17. Koopman, B. (1940). The bases of probability. Bulletin of the American Mathematical Society, 46, 763–774.

    Article  Google Scholar 

  18. Kyburg, H. (1956). The justification of induction. Journal of Philosophy, 53, 394–400.

    Article  Google Scholar 

  19. Kyburg, H. (1961). Probability and the logic of rational belief. Middletow: Wesleyan University Press.

    Google Scholar 

  20. Kyburg, H. (1974). The logical foundations of statistical inference. Dordrecht: Reidel Publishing Company.

    Book  Google Scholar 

  21. Kyburg, H., & Teng, C. (2001). Uncertain inference. Cambridge: Cambridge University Press.

    Book  Google Scholar 

  22. Levi, I. (1974). On indeterminate probabilities. Journal of Philosophy, 71, 391–418.

    Article  Google Scholar 

  23. Lewis, D. (1980). A subjectivist’s guide to objective chance. In R. C. Jeffrey (Ed.), Studies in inductive logic and probability, Vol II. Berkeley and Los Angeles: University of California Press.

    Google Scholar 

  24. Maher, P. (1993). Betting on theories. Cambridge: Cambridge University Press.

    Book  Google Scholar 

  25. McCarthy, J. (1980). Circumscription - a form of non-monotonic reasoning. Artificial Intelligence, 13, 27–31.

    Article  Google Scholar 

  26. McDermott, D., & Doyle, J. (1980). Non-monotonic logic I. Artificial Intelligence, 13, 41–72.

    Article  Google Scholar 

  27. McGrew, T. (2001). Direct inference and the problem of induction. The Monist, 84, 153–174.

    Article  Google Scholar 

  28. Osherson, D. (2002). Order dependence and Jeffrey conditionalization. Unpublished paper available at: http://www.princeton.edu/~osherson/papers/jeff3.pdf.

  29. Paris, J., & Vencovská, A. (1990). A note on the inevitability of maximum entropy. International Journal of Approximate Reasoning, 4, 183–223.

    Article  Google Scholar 

  30. Paris, J., & Vencovská, A. (1997). In defence of the maximum entropy inference process. International Journal of Approximate Reasoning, 17, 77–103.

    Article  Google Scholar 

  31. Pollock, J. (1967). Criteria and our knowledge of the material world. Philosophical Review, 76, 28–60.

    Article  Google Scholar 

  32. Pollock, J. (1990). Nomic probability and the foundations of induction. Oxford University Press.

  33. Pollock, J. (1995). Cognitive carpentry: a blueprint for how to build a person. Cambridge: MIT Press.

    Google Scholar 

  34. Reichenbach, H. (1935). Wahrscheinlichkeitslehre: eine Untersuchung über die logischen Und mathematischen Grundlagen der Wahrscheinlichkeitsrechnung. English translation: (1949). The theory of probability, an inquiry into the logical and mathematical foundations of the calculus of probability. University of California Press.

  35. Reiter, R. (1980). A logic for default reasoning. Artificial Intelligence, 13, 81–132.

    Article  Google Scholar 

  36. Rescher, N. (1977). Dialectics. New York: SUNY Albany Press.

    Google Scholar 

  37. Schurz, G. (1997). Probabilistic default reasoning based on relevance and irrelevance assumptions. In D. Gabbay et al. (Eds.), Qualitative and quantitative practical reasoning (pp. 536–553). Berlin: Springer.

    Chapter  Google Scholar 

  38. Schurz, G. (2005). Non-monotonic reasoning from an evolutionary viewpoint: ontic, logical and cognitive foundations. Synthese, 146(1–2), 37–51.

    Article  Google Scholar 

  39. Smith, C. (1961). Consistency in statistical inference and decision. Journal of the Royal Statistical Society, Series B, 23, 1–37.

    Google Scholar 

  40. Stove, D. (1986). The rationality of induction. Oxford: Clarendon.

    Google Scholar 

  41. Thorn, P. (2011). Undercutting defeat via reference properties of differing Arity: a reply to Pust. Analysis, 71(4), 662–667.

    Article  Google Scholar 

  42. Thorn, P. (2012). Two problems of direct inference. Erkenntnis, 76(3), 299–318.

    Article  Google Scholar 

  43. Toulmin, S. (1958). The place of reason in ethics. Cambridge University Press.

  44. Touretzky, D., Horty, J., & Thomason, R. (1987). A clash of intuitions: the current state of monotonic multiple inheritance systems. In Proceedings of the Tenth international Joint Conference on Artificial Intelligence pp. 476–482.

  45. Van Fraassen, B. (1989). Laws and symmetry. Oxford University Press.

  46. Van Frasssen, B. (1990). Figures in a probability landscape. In J. M. Dunn & A. Gupta (Eds.), Truth and consequences (pp. 345–356). Dordrecht: Kluwer Academic Publishers.

    Chapter  Google Scholar 

  47. Venn, J. (1866). The logic of chance. New York: Chelsea Publishing Company.

    Google Scholar 

  48. Wagner, C. (2002). Probability kinematics and commutativity. Philosophy of Science, 69(2), 266–278.

    Article  Google Scholar 

  49. Walley, P. (1991). Statistical reasoning with imprecise probabilities. London: Chapman and Hall.

    Book  Google Scholar 

  50. Williams, D. (1947). The ground of induction. Cambridge: Harvard University Press.

    Book  Google Scholar 

  51. Williamson, J. (2007). Motivating objective Bayesianism: from empirical constraints to objective probabilities. In W. L. Harper & G. R. Wheeler (Eds.), Probability and inference: essays in honor of Henry E. Kyburg Jr. London: College Publications.

    Google Scholar 

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Thorn, P.D. Defeasible Conditionalization. J Philos Logic 43, 283–302 (2014). https://doi.org/10.1007/s10992-012-9263-1

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