Abstract
Ockhamism implies that future contingents may be true, their historical contingency notwithstanding. It is thus opposed to both the Peircean view according to which all future contingents are false, and Supervaluationist Indeterminism according to which all future contingents are neither true nor false. The paper seeks to defend Ockhamism against two charges: the charge that it cannot meet the requirement that truths be grounded in reality, and the charge that it proves incompatible with objective indeterminism about the future. In each case, the defence draws on the idea that certain truths are truths only courtesy of others and of what makes the latter true. After introduction of the Ockhamist view, its competitors and implications, a suitable definition of grounded truth is being devised that both is faithful to the spirit of the grounding-requirement and allows the Ockhamist to heed that requirement quite comfortably. Then two senses in which the future might be open are being introduced, indeterminacy as failure of predetermination by past and present facts, and indeterminacy as failure of entailment by past and present truths. It is argued that while openness in the former sense, but not in the latter sense, coheres with the Ockhamist view, it is only openness in the former sense that matters for objective indeterminism.
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Notes
As Thomason notes, Prior’s formal characterisation of Ockhamism is at best incomplete, as it makes truth relative to a history without saying anything about which history, if any, is the one relative to which future contingents ought to be evaluated (Thomason 1970: 269–71). See Øhrstrøm (2009) for arguments showing that the position properly called ‘Ockhamism’ requires such a privileged history—the notorious thin red line. If there is such a privileged history, then truth (at a moment) simpliciter can be understood in terms of truth (at a moment) relative to that history.
I am indebted to an anonymous referee for calling my attention to the need for this caveat.
If all the laws, as well as the claim that they are laws and nothing else is, may be taken to be made true at some particular time, the modality involved may be construed as metaphysical necessity. If this condition is not met, the modality involved may instead be construed as nomological necessity. However, even then one might insist on a reading of ‘necessarily, A’ on which it says that A is metaphysically necessary. It all depends on whether one wishes to account for the nontrivial examples mentioned in the first paragraph of the section entitled “The Ockhamist’s Narrative”, which is nothing the Ockhamist qua Ockhamist is committed to.
… or, for that matter, in terms of determinately grounded truth, where ‘determinately’ is some primitive non-epistemic notion. This is precisely where the Ockhamist parts company with Barnes and Cameron (2009) (see the section entitled “Future Contingents” above).
According to McCall’s preferred dynamic account (what he calls ‘Theory D’), different ‘universe pictures’, displaying forward branching, are adequate representations of reality at different times, with branches falling off, as it were, as time goes by (McCall 1976: 342–43). McCall is adamant that Theory D is not simply a dynamic version of the Everett-Wheeler conception according to which reality is ‘multiple’ and so, as Lewis would put it, ‘many ways’ (McCall 1976: 342; Lewis 1986: 207–208). It thus becomes unclear why, as soon as it is viewed sub specie aeternitatis, Theory D does not collapse into the Ockhamist’s account (what he calls ‘Theory B’), according to which there is a thin red line, while at each time there are many historically possible continuations of the present. Faced with the challenge, McCall resorts to semantic considerations (McCall 1976: 350). Once the familiar kind of supervaluationist semantics is in place (McCall 1976: 355–60), the threat of collapse can indeed successfully be averted. However, it is hard to see how this semantic manoeuvre to define truth as supertruth can carry any metaphysical weight, unless it is being presupposed that there is a metaphysically relevant notion of indeterminacy the Ockhamist fails to capture, viz. that different continuations of the present are consistent with all present and past truths (cf. McCall’s discussion of timeless vs temporal truth on pp. 354–56). As was argued above, given the conception of statements about the future as being true courtesy of what will happen, it becomes very doubtful that this is a metaphysically relevant notion, or anyway one according to which the future is indeed indeterminate.
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Acknowledgements
I am grateful to the following colleagues, students and friends for their critical comments that helped to improve the paper significantly: Fabrice Correia, Manuel García-Carpintero, Carl Hoefer, Dan López de Sa, Giovanni Merlo, Ivan Milic, Nathan Oaklander, Pablo Rychter, Albert Solé, Stephan Torre, and Richard Woodward. The research leading to these results has received funding from the European Community’s 7th Framework Programme under grant agreement PITN-GA-2009-238128, and was also partially funded by the Consolider-Ingenio project CSD2009-0056 and the project FFI-2008-06153, both financed by the Spanish Ministry of Science and Innovation (MICINN).
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Rosenkranz, S. In Defence of Ockhamism. Philosophia 40, 617–631 (2012). https://doi.org/10.1007/s11406-011-9337-2
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DOI: https://doi.org/10.1007/s11406-011-9337-2