Abstract
Many metaphysical controversies can be understood as debates over whether some alleged entities are metaphysically possible. (Examples: Are zombies possible? Is atomless gunk possible? Are extended simples possible? etc.) No doubt, with regard to these matters, we may have opinions or theories, commonsensical or sophisticated. But do we have knowledge of them? Can we really know that something is metaphysically possible, and if so, how? Several different answers have been offered in the literature, intending to illustrate how we may have knowledge of metaphysical modality. In this paper, I concentrate on a proposal by Timothy Williamson (2007). On this account, our alleged knowledge of metaphysical modality is justified by and grounded in our capacity to handle ordinary mundane counterfactual conditionals. However, I argue that Williamson’s account fails, mainly because the modality involved in ordinary mundane counterfactuals is causal, and thus our capacity to handle them still falls short of giving us any knowledge of metaphysical modality. In the end of the paper, I also provide my own answer to the question. My answer is a sceptical one: we do not really have knowledge of metaphysical modality. But such ignorance is harmless, or so I argue.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Notes
I do not mean to suggest these as definitions for logical or physical modality. The informal characterisations here are only intended to illustrate the point that modal knowledge is comparatively uncontroversial when the modality involved is logical or physical. Of course extreme sceptics could still cast doubt even on our knowledge of such logical or physical modality. However, due to the limited scope of the paper, which mainly concerns ‘metaphysical modality’, I shall simply assume that we can have modal knowledge of such a kind that is comparatively uncontroversial, so as to examine whether it can be extended to cases involving metaphysical modality.
The intelligibility of de re modality had been seriously challenged in the previous century, most notably by Quine. However, after Kripke (1980) and Putnam’s (1975) defence, the very idea of de re modality is no longer taken to be dubious, and some related notions (such as ‘essence’, ‘power’, ‘ontological dependence’, ‘grounding’, etc.) are even postulated as primitive and fundamental for constructing various metaphysical systems (cf. Fine 1994, 1995; Correia and Schnieder 2012). But this is not to say that modal scepticism has been answered. Even if we no longer cast doubt on the intelligibility of modal claims, there is still the question of whether we can have cognitive access to them.
I here assimilate mathematical possibilities to logical possibilities for the sake of simplicity.
Williamson’s example is this: ‘If two marks had been nine inches apart, they would have been at least nineteen centimeters apart’ (Williamson 2007, p. 166). Suppose someone makes this judgment by imagining two such marks and perceptually measuring it, rather than deriving it from inference. This judgment is difficult to classify as a priori or a posteriori. Yablo (2002) offers a similar example concerning oval.
‘An attractive suggestion is that some kind of simulation is involved…. It is just a hint of an answer to say that in simulation cognitive faculties are run offline. The cognitive faculties that would be run online to evaluate A and B as free-standing sentences are run offline in the evaluation of the counterfactual conditional A□→B’ (Williamson 2007, p. 147).
Cf. (Tahko 2012, p. 107).
In his reply to Peacocke, Williamson spends more effort in attacking the ‘alternative model’ Peacocke offers as being guilty of the use-mention confusion (cf. Williamson 2011b). Whilst I generally agree with Williamson’s attack, I omit it here because it is not directly relevant to my point.
I am grateful to an anonymous reviewer for raising this question.
I am grateful to an anonymous reviewer for raising this question.
Violations of the laws of nature are good examples. Of course some philosophers would still disagree and claim instead that all laws are metaphysically necessary (e.g., Bird 2007). Due to the limited scope of the paper, however, I shall simply assume that the laws of nature are metaphysically contingent.
In this sense my objection here bears some similarity to the objection raised by Roca-Royes and Tahko (see the discussion above) concerning whether Williamson has successfully justified our capacity to know what to hold fixed. But there is a crucial difference. Whereas in their objection the ‘constitutive facts’ are taken on a par with metaphysical modalities to share the same epistemic challenge, I am more inclined to take them as a kind of causal or scientific truths that can be learned in such disciplines as chemistry or physics. (This is why I think constitutive knowledge presents no problem to Williamson’s account.)
This is not to say that metaphysical disputes like these are mere nonsense. They are certainly meaningful questions. We may have opinions about them; we may have good intuitions about them; and we may even have good arguments about them. Our beliefs or disbeliefs about them may also affect our attitude towards something important in our life. The point is simply that these opinions, intuitions, arguments, or attitudes are not knowledge.
References
Bird, A. (2007). Nature’s metaphysics: laws and properties. Oxford: Oxford University Press.
Boghossian, P. (2011). Williamson on the a priori and the analytic. Philosophy and Phenomenological Research, 82(2), 488–497.
Chalmers, D. J. (2006). The foundations of two-dimensional semantics. In M. Garcia-Carpintero & J. Macia (Eds.), Two-dimensional semantics. Oxford: Oxford University Press.
Correia, F., & Schnieder, B. (Eds.). (2012). Metaphysical grounding: Understanding the structure of reality. Cambridge: Cambridge University Press.
Fine, K. (1994). Essence and modality. Philosophical Perspectives, 8, 1–16.
Fine, K. (1995). Senses of essence. In W. Sinnott-Armstrong, D. Raffman, & N. Asher (Eds.), Modality, morality and belief: Essays in honor of Ruth Barcan Marcus (pp. 53–73). Cambridge: Cambridge University Press.
Kment, B. (2006). Counterfactuals and the analysis of necessity. Philosophical Perspectives, 20(1), 237–302.
Kripke, S. A. (1980). Naming and necessity. Cambridge: Harvard University Press.
Lowe, E. J. (2008). Two notions of being: entity and essence. Philosophy, 62, 23–48.
Lowe, E. J. (2012). What is the source of our knowledge of modal truths? Mind, 121(484), 919–950.
Peacocke, C. (2011). Understanding, modality, logical operators. Philosophy and Phenomenological Research, 82(2), 472–480.
Putnam, H. (1975). The meaning of ‘Meaning’. In Mind, language and reality: Philosophical papers, volume 2 (pp. 215–271). Cambridge: Cambridge University Press.
Roca-Royes, S. (2011a). Conceivability and De Re modal knowledge. Noûs, 45(1), 22–49.
Roca-Royes, S. (2011b). Modal knowledge and counterfactual knowledge. Logique et Analyse, 54(216), 537–552.
Tahko, T. E. (2012). Counterfactuals and modal epistemology. Grazer Philosophische Studien, 86(1), 93–115.
Williamson, T. (2007). The philosophy of philosophy. Oxford: Blackwell.
Williamson, T. (2011a). Précis of the philosophy of philosophy. Philosophy and Phenomenological Research, 82(2), 470–471.
Williamson, T. (2011b). Reply to Boghossian. Philosophy and Phenomenological Research, 82(2), 498–506.
Williamson, T. (2011c). Reply to Peacocke. Philosophy and Phenomenological Research, 82(2), 481–487.
Yablo, S. (2002). Coulda, woulda, shoulda. In T. S. Gendler & J. Hawthorne (Eds.), Conceivability and possibility (pp. 441–492). Oxford: Oxford University Press.
Acknowledgments
I would like to thank two anonymous referees for their helpful comments, as well as the Ministry of Science and Technology, Taiwan (MOST) for the financial support (Project: 102-2410-H-002-229-MY2)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Deng, DM. On the Alleged Knowledge of Metaphysical Modality. Philosophia 44, 479–495 (2016). https://doi.org/10.1007/s11406-016-9699-6
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11406-016-9699-6