Abstract
According to Hans Kamp and Frank Vlach, the two-dimensional tense operators “now” and “then” are ineliminable in quantified tense logic. This is often adduced as an argument against tense logic, and in favor of an extensional account that makes use of explicit quantification over times. The aim of this paper is to defend tense logic against this attack. It shows that “now” and “then” are eliminable in quantified tense logic, provided we endow it with enough quantificational structure. The operators might not be redundant in some other systems of tense logic, but this merely indicates a lack of quantificational resources and does not show any deep-seated inability of tense logic to express claims about time. The paper closes with a brief discussion of the modal analogue of this issue, which concerns the role of the actuality operator in quantified modal logic.
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References
Boolos, G. (1998). Logic, Logic, and Logic. Cambridge, Mass: Harvard University Press.
Bostock, D. (1988). Necessary truth and a priori truth. Mind, 97, 343–379.
Bricker, P. (1989). Quantified modal logic and the plural de re. In P. French, T. Uehling, & H. Wettstein (Eds.), Midwest Studies in Philosophy (Vol. XIV, pp. 372–394). Minneapolis: University of Minnesota Press.
Burgess, J. P. (1984). Basic tense logic. In Gabbay and Guenther [10] (pp. 89–133).
Burgess, J. P., Hazen, A., & Lewis, D. (1991). Appendix on pairing. In D. Lewis (Ed.), Parts of Classes (pp. 121–149). Oxford: Blackwell.
Cresswell, M. J. (1990). Entities and Indices. Dordrecht: Kluwer.
Crossley, J., & Humberstone, L. (1977). The logic of ‘actually’. Reports on Mathematical Logic, 8, 11–29.
Forbes, G. (1989). Languages of Possibility. Oxford: Blackwell.
Gabbay, D. (1975). Model theory for tense logics. Annals of Mathematical Logic, 8, 185–236.
Gabbay, D., & Guenther, F. (Eds.) (1984). Handbook of Philosophical Logic (Vol. II). Dordrecht: Kluwer.
Garson, J. (2001). Quantification in modal logic. In Gabbay and Guenther [10] (pp. 249–307).
Hazen, A. (1976). Expressive completeness in modal languages. Journal of Philosophical Logic, 5, 25–46.
Hazen, A. (1978). The eliminability of the actuality operator in propositional modal logic. Notre Dame Journal of Formal Logic, 19, 617–622.
Hazen, A. (1990). Actuality and quantification. Notre Dame Journal of Formal Logic, 31, 498–508.
Hodes, H. (1984). Axioms for actuality. Journal of Philosophical Logic, 13, 27–34.
Hodes, H. (1984). Some theorems on the expressive limitations of modal languages. Journal of Philosophical Logic, 13, 13–26.
Kamp, H. (1968). Tense logic and the theory of linear orders. Ph.D. thesis, University of California, Los Angeles.
Kamp, H. (1971). Formal properties of ‘now’. Theoria, 37, 227–273.
Lewis, D. (2004). Tensed quantifiers. In D. Zimmerman (Ed.), Oxford Studies in Metaphysics (Vol. I, pp. 3–14). Oxford: Clarendon Press.
Meyer, U. (2005). The presentist’s dilemma. Philosophical Studies, 122, 213–225.
Meyer, U. (2006). Worlds and times. Notre Dame Journal of Formal Logic, 47, 25–37.
Meyer, U. (2008). Times in tense logic. Unpublished manuscript.
Prior, A. (1957). Time and Modality. Oxford: Clarendon Press.
Prior, A. (1968). “Now.” Noûs, 2, 101–119. See also: Prior, A. (1968). “Now” corrected and condensed. Noûs, 2, 411–412.
Quine, W. V. (1951). Ontology and ideology. Philosophical Studies, 2, 11–15.
Quine, W. V. (1980). On what there is. In From a Logical Point of View (2nd ed., pp. 1–19). Cambridge, Mass: Harvard University Press.
Segerberg, K. (1973). Two-dimensional modal logic. Journal of Philosophical Logic, 2, 77–97.
Shapiro, S. (1991). Foundations without Foundationalism. Oxford: Clarendon Press.
Thomason, R. (1969). Modal logic and metaphysics. In K. Lambert (Ed.), The Logical Way of Doing Things (pp. 119–146). New Haven: Yale University Press.
van Benthem, J. (1977). Tense logic and standard logic. Logique et Analyse, 80, 395–437.
Vlach, F. (1973). ‘Now’ and ‘then’: A formal study in the logic of tense anaphora. Ph.D. thesis, University of California, Los Angeles.
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Meyer, U. ‘Now’ and ‘Then’ in Tense Logic. J Philos Logic 38, 229–247 (2009). https://doi.org/10.1007/s10992-008-9090-6
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DOI: https://doi.org/10.1007/s10992-008-9090-6