Abstract
During the last quarter of a century, a number of philosophers have become attracted to the idea that necessity can be analyzed in terms of a hyperintensional notion of essence. One challenge for proponents of this view is to give a plausible explanation of our modal knowledge. The goal of this paper is to develop a strategy for meeting this challenge. My approach rests on an account of modality that I developed in previous work, and which analyzes modal properties in terms of the notion of a metaphysical law (which is a generalization of the concept of an essential truth). I discuss what information about the metaphysical laws (including essential truths) is required for modal knowledge. Moreover, I describe two ways in which we might be able to acquire this information. The first way employs inference to the best explanation. The metaphysical laws, including the essential truths, play a crucial role in causal and grounding explanations and we can gain knowledge of these laws by abductive inferences from facts of which we have perceptual or a priori knowledge. The second way of gaining information about the metaphysical laws rests on knowledge that is partly constitutive of competence with the concepts that are needed to express the relevant information. Finally, I consider how knowledge of the metaphysical laws can be used to establish modal claims, paying special attention to the much-discussed connection between conceiving and possibility.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Notes
See Williamson (2008, pp. 171–175, 2017, 2018), for a defense of the claim that all counterpossibles are true. (Also see Lewis 1973a; Stalnaker 1968, 1996.) Many other philosophers, including myself, find the claim implausible and have argued against it (see Nolan 1997; Vander Laan 2004; Kment 2006b, 2014; Brogaard and Salerno 2007a, b, 2013; Lange 2009: sct. 2.7; Berto et al. (2018). The debate about the status of counterpossibles is ongoing and I will not be able to join it here.
This view departs from Nolan’s by adopting a consistency requirement on worlds. However, we can think of this requirement as no more than a useful idealization that might eventually be abandoned in the course of a full development of the position.
The graded form of modality I described is similar to what Kratzer (1991: scts. 3.3, 5) calls “circumstantial modality,” which she defines in terms of a closeness ordering. However, there is an important difference in the order of explanation and a closely related further difference between the non-reductive character of her account and the reductive nature of my own. I start with a non-modal concept of a world and a notion of comparative closeness between worlds that is defined non-modally, and I use them to give a non-modal definition of a graded notion of possibility. The graded notion in turn is used to define metaphysical possibility (as well as other specific grades of possibility, such as nomic possibility): The metaphysically possible propositions are those that have at least a certain degree of possibility. Similarly, the metaphysically possible worlds are all and only those whose actualization has at least a certain degree of possibility. In other words, they are the worlds that are actualized at some world within a certain distance from actuality or, equivalently and more simply, they are the worlds that are located within that distance from actuality. By contrast, Kratzer starts with an unanalyzed notion of a possible world, and then defines the closeness ordering and the graded notion of possibility in terms of it. Her view is non-reductive.
… except perhaps in a few special cases, for example those in which we gain modal knowledge through testimony.
This is a modernized version of the train of thought that can be found, for example, in Kant (1787), p. 43. David Hume’s idea that we do not perceive necessary connections in the objects is in a similar spirit.
This sketch is somewhat simplified. For further details about the standards is somewhat simplified. For further details about the standards of closeness, see Kment (2014: sct. 7.1, chs. 8–9).
A real definition of an individual is a singular proposition about that individual, wherefore stating such a real definition requires a directly referential name. The most common expressions for {2}, such as “the singleton of two” and “{2},” are not obviously directly referential, which is why I needed to introduce the term “N”.
(4) may not itself be a metaphysical law but may instead be a corollary of a more general principle of plenitude for properties that is a metaphysical law (in which case it is the more general principle rather than (4) that covers the relevant instances of grounding).
I am assuming that there is a sense in which a sentence can be said to express a Russellian proposition. To be more precise, I believe that on one possible way of individuating the truth-conditions of sentences, the truth-condition of any (truth-apt) sentence is the same as that of some Russellian proposition. That does not imply that the Russellian proposition can serve as the semantic content of the sentence for all purposes.
By a “truth about the metaphysical laws,” I mean a proposition that is either of the form It is a metaphysical law that P or of the form It is not a metaphysical law that P. (2) entails that a proposition is metaphysically necessary iff it holds at all worlds that have the same metaphysical laws as actuality and that perfectly conform to these laws, i.e. at all worlds where the actual metaphysical laws and the actual truths about the metaphysical laws hold. That entails that a proposition is metaphysically necessary iff it is logically entailed by the metaphysical laws and the truths about the metaphysical laws.
All Russellian singular propositions that make simple non-identity claims are of the form a is not b. Moreover, all false propositions of this form, i.e. all those that deny that a certain thing a is identical with a, contain the object a as a constituent twice over and are therefore of the form a is not a. All Russellian propositions that are of the first but not of the second form are true.
The English sentence “Mars is not Venus” also has the two formal features I described—it is of the form a is not b but not of the form a is not a—but it is not true in virtue of having these two features. (After all, there are many false English sentences that have the same two features, such as “Hesperus is not Phosphorus.”) When an English sentence is about the same entity twice over, this need not be reflected in its logical form in the way it always is in the case of Russellian propositions. The fact that two different names occur in “Hesperus is not Phosphorus” therefore does not guarantee that the sentence is about two different individuals, and therefore does not guarantee the sentence’s truth.
It does not matter whether the two toy accounts can be taken seriously as theories about what is expressed by (5). I introduced them merely to illustrate the fact that we cannot in general explain why a given sentence is necessary without making controversial assumptions about the contents of its constituent expressions.
See Peacocke (1999) (in particular pp. 1–4, 119–75) for an extended discussion of how knowledge that is partly constitutive of concept possession can be used to acquire modal knowledge. His views differ from mine.
…rather than expressing the conjunctive condition of being female and being a fox, as on the first of the two toy accounts considered in the previous section.
Representing a scenario to oneself that strikes one as possible is another process that might be called “conceiving (of the scenario)”
For comments and suggestions, I am indebted to Mark Johnston, Antonella Mallozzi, Daniel Nolan, Gideon Rosen, Jonathan Schaffer, Anand Vaidya, the audience of a talk I gave at the Conceivability and Modality conference at Sapienza University in Rome in June 2017 and to two referees for Synthese.
References
Audi, P. (2012a). A clarification and defence of the notion of grounding. In F. Correia & B. Schnieder (Eds.), Metaphysical grounding: Understanding the structure of reality (pp. 101–121). Cambridge: Cambridge University Press.
Audi, P. (2012b). Grounding: Toward a theory of the in-virtue-of relation. The Journal of Philosophy, 109, 685–711.
Bennett, J. (1984). Counterfactuals and temporal direction. Philosophical Review, 93, 57–91.
Bennett, J. (2001). On forward and backward counterfactual conditionals. In G. Preyer & F. Siebelt (Eds.), Reality and humean supervenience (pp. 177–202). Lanham: Rowman and Littlefield.
Bennett, J. (2003). A philosophical guide to conditionals. Oxford: Clarendon Press.
Bennett, K. (2004). Spatio-temporal coincidence and the grounding problem. Philosophical Studies, 118, 339–371.
Bennett, K. (2011). Construction area (no hard hat required). Philosophical Studies, 154, 79–104.
Bennett, K. (2017). Making things up. Oxford: Oxford University Press.
Berto, F., French, R., Priest, G., & Ripley, D. (2018). Williamson on counterpossibles. Journal of Philosophical Logic, 47, 693–713.
Brogaard, B., & Salerno, J. (2007a). Why counterpossibles are non-trivial. The Reasoner, 1(1), 5–6.
Brogaard, B., & Salerno, J. (2007b). Williamson on counterpossibles. The Reasoner, 1(3), 5–6.
Brogaard, B., & Salerno, J. (2013). Remarks on counterpossibles. Synthese, 190, 639–660.
Chalmers, D. (2002). Does conceivability entail possibility? In T. Gendler & J. Hawthorne (Eds.), Conceivability and possibility (pp. 145–200). Oxford: Oxford University Press.
Daly, C. (2012). Scepticism about grounding. In F. Correia & B. Schnieder (Eds.), Metaphysical grounding: Understanding the structure of reality (pp. 81–100). Cambridge: Cambridge University Press.
Dorr, C. (2016). To be F is to be G. Philosophical Perspectives, 30, 39–134.
Fine, K. (1994). Essence and modality. Philosophical Perspectives, 8, 1–16.
Fine, K. (1995). The logic of essence. Journal of Philosophical Logic, 24, 241–273.
Fine, K. (2012a). Guide to ground. In F. Correia & B. Schnieder (Eds.), Metaphysical grounding: Understanding the structure of reality (pp. 37–80). Cambridge: Cambridge University Press.
Fine, K. (2012b). The pure logic of ground. Review of Symbolic Logic, 5, 1–25.
Gendler, T., & Hawthorne, J. (Eds.). (2002). Conceivability and possibility. Oxford: Oxford University Press.
Glazier, M. (2016). Laws and the completeness of the fundamental. In M. Jago (Ed.), Reality making (pp. 11–37). Oxford: Oxford University Press.
Hale, B. (2013). Necessary beings: An essay on ontology, modality, and the relations between them. Oxford: Oxford UP.
Hill, C. (2006). Modality, modal epistemology, and the metaphysics of consciousness. In S. Nichols (Ed.), The architecture of the imagination: New essays on pretense, possibility, and fiction (pp. 205–235). Oxford: Oxford University Press.
Hofweber, T. (2009). Ambitious, yet modest, metaphysics. In D. Chalmers, D. Manley, & R. Wasserman (Eds.), Metametaphysics: New essays on the foundations of ontology (pp. 260–289). Oxford: Clarendon Press.
Jackson, F. (1998). From metaphysics to ethics: A defence of conceptual analysis. Oxford: Oxford University Press.
Jackson, F. (2010). Language, names and information. Walden: Wiley-Blackwell.
Jenkins, C. (2010). Concepts, experience, and modal knowledge. Philosophical Perspectives, 24, 255–279.
Jenkins, C. (2011). Is metaphysical dependence irreflexive? The Monist, 94, 267–276.
Johnston, M., & Leslie, S.-J. (2012). Concepts, Analysis, Generics and the Canberra Plan. Philosophical Perspectives, Philosophy of Mind, 26, 113–171.
Kant, I. (1787) Kritik der reinen Vernunft Riga: J. F. Hartknoch, translated into English by Norman Kemp Smith as Immanuel Kant’s Critique of Pure Reason London: Macmillan 1963.
Kment, B. (2006a). Counterfactuals and explanation. Mind, 115, 261–310.
Kment, B. (2006b). Counterfactuals and the analysis of necessity. Philosophical Perspectives, 20, 237–302.
Kment, B. (2014). Modality and explanatory reasoning. Oxford: Oxford UP.
Kment, B. (2015). Modality, metaphysics, and method. In C. Daly (Ed.), The palgrave handbook of philosophical methods. Basingstoke: Palgrave Macmillan.
Kment, B. (2018). Chance and the structure of modal space. Mind, online at https://academic.oup.com/mind/advance-article-abstract/doi/10.1093/mind/fzy001/4976530.
Koslicki, K. (2012). Essence, necessity and explanation. In Tuomas Tahko (Ed.), Contemporary aristotelian metaphysics (pp. 187–206). Cambridge: Cambridge University Press.
Kratzer, A. (1981). The notional category of modality. In H. J. Eikmeyer & H. Rieser (Eds.), Words, worlds, and contexts: New approaches in word semantics (pp. 38–74). Berlin: W. de Gruyter.
Kratzer, A. (1991). Modality. In A. von Stechow & D. Wunderlich (Eds.), Semantics: An international handbook of contemporary research (pp. 639–650). Berlin: W. de Gruyter.
Kripke, S. (1981). Naming and necessity. Oxford: Blackwell.
Lange, M. (1999). Laws, counterfactuals, stability, and degrees of lawhood. Philosophy of Science, 66, 243–267.
Lange, M. (2000). Natural laws in scientific practice. New York: Oxford University Press.
Lange, M. (2005). A counterfactual analysis of the concepts of logical truth and necessity. Philosophical Studies, 125, 277–303.
Lange, M. (2009). Laws and lawmakers. Oxford: Oxford University Press.
Leslie, Sarah-Jane. (2011). Essence, plenitude, and paradox. Philosophical Perspectives, 25, 277–296.
Lewis, D. (1973a). Counterfactuals. Cambridge: Harvard University Press.
Lewis, D. (1973b). Counterfactuals and comparative possibility. Journal of Philosophical Logic, 2, 418–446.
Lewis, D. (1986). Counterfactual dependence and time’s arrow. Philosophical papers (Vol. 2, pp. 32–66). New York and Oxford: Oxford University Press.
Lowe, E. J. (2006). The four-category ontology. Oxford: Clarendon Press.
Lowe, E. J. (2007). A problem for a posteriori essentialism concerning natural kinds. Analysis, 67, 286–292.
Lowe, E. J. (2012). What is the source of our knowledge of modal truths? Mind, 121, 919–950.
Mallozzi, A. (2018). Putting modal metaphysics first. Synthese, 2018, 1–20.
Mares, E. (1997). Who’s afraid of impossible worlds? Notre Dame Journal of Formal Logic, 38, 516–526.
McFetridge, I. (1990). Logical necessity: Some issues. In J. Haldane & R. Scruton (Eds.), Logical necessity, and other essays (pp. 135–154). London: Aristotelian Society.
Nolan, D. (1997). Impossible worlds: A modest approach. Notre Dame Journal of Formal Logic, 38, 535–573.
Nolan, D. (2013). Impossible worlds. Philosophy Compass, 8, 360–372.
Nolan, D. (2017). Naturalised modal epistemology. In R. Fischer & F. Leon (Eds.), Modal epistemology after rationalism. Dordrecht: Springer.
Peacocke, C. (1999). Being known. Oxford: Oxford University Press.
Putnam, H. (1975). The meaning of ‘meaning’. In Mind, Language, and Reality. Philosophical Papers, Volume 2. Cambridge: Cambridge University Press.
Rayo, A. (2013). The construction of logical space. Oxford: Oxford University Press.
Roca-Royes, S. (2017). Similarity and possibility: An epistemology of de re modality for concrete entities. In R. Fischer & F. Leon (Eds.), Modal epistemology after rationalism. Dordrecht: Springer.
Rosen, G. (2006). The limits of contingency. In F. MacBride (Ed.), Identity and modality (pp. 13–39). Oxford: Oxford University Press.
Rosen, G. (2010). Metaphysical dependence: Grounding and reduction. In B. Hale & A. Hoffmann (Eds.), Modality: Metaphysics, logic, and epistemology (pp. 109–136). Oxford: Oxford University Press.
Rosen, G. (2015). Real definition. Analytic Philosophy, 56, 189–209.
Rosen, G. (2017). Ground by law. Philosophical Issues, 27, 279–301.
Routley, R. (1989). Philosophical and linguistic inroads: Multiply intensional relevant logics. In J. Norman & R. Sylvan (Eds.), Directions in Relevant Logic (Chap. 19). Dordrecht: Kluwer.
Schaffer, J. (2009). On what grounds what. In D. Chalmers, D. Manley, & R. Wasserman (Eds.), Metametaphysics (pp. 347–383). Oxford: Oxford University Press.
Schaffer, J. (2016). Grounding in the image of causation. Philosophical Studies, 173, 49–100.
Schaffer, J. (2017). Laws for metaphysical explanation. Philosophical Issues, 27, 302–321.
Sider, T. (2011). Writing the book of the world. Oxford: Oxford University Press.
Stalnaker, R. (1968). A theory of conditionals. In N. Rescher (Ed.), Studies in logical theory (pp. 98–112). Blackwell, Oxford: American philosophical quarterly monograph series 2.
Stalnaker, R. (1996). Impossibilities. Philosophical topics, 24, 193–204.
Tahko, T. (2018). The Epistemology of essence. In A. Carruth, S. C. Gibb, & J. Heil (Eds.), Ontology, modality, mind: Themes from the metaphysics of E. J. Lowe (pp. 93–110). Oxford: Oxford UP.
Vander Laan, D. (2004). Counterpossibles and similarity. In F. Jackson & G. Priest (Eds.), Lewisian themes: The philosophy of David K Lewis (pp. 258–275). Oxford: Oxford UP.
Williamson, T. (2005). Armchair philosophy, metaphysical modality and counterfactual thinking. Proceedings of the Aristotelian Society, 105, 1–23.
Williamson, T. (2008). The philosophy of philosophy. Malden: Wiley-Blackwell.
Williamson, T. (2017). Counterpossibles in semantics and metaphysics. Argumenta, https://ora.ox.ac.uk/objects/uuid:a05fab31-5ea9-4f65-97e2-db15cbbfaa46.
Williamson, T. (2018). Counterpossibles. Topoi, 37, 357–368.
Wilsch, T. (2015a). The nomological account of ground. Philosophical Studies, 172, 3293–3312.
Wilsch, T. (2015b). The deductive-nomological account of metaphysical explanation. Australasian Journal of Philosophy, 94, 1–23.
Wilson, J. (2014). No work for a theory of grounding. Inquiry, 57, 535–579.
Yablo, S. (1993). Is conceivability a guide to possibility? Philosophy and Phenomenological Research, 53, 1–42.
Zalta, E. N. (1997). A classically-based theory of impossible worlds. Notre Dame Journal of Formal Logic, 38, 640–660.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kment, B. Essence and modal knowledge. Synthese 198 (Suppl 8), 1957–1979 (2021). https://doi.org/10.1007/s11229-018-01903-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11229-018-01903-1