pp 1–27 | Cite as

Empirical incoherence and double functionalism

  • Sam BaronEmail author
S.I.: Spacetime Functionalism


Recent work on quantum gravity (QG) suggests that neither spacetime nor spatiotemporally located entites exist at a fundamental level. The loss of both brings with it the threat of empirical incoherence. A theory is empirically incoherent when the truth of that theory undermines the empirical justification for believing it. If neither spacetime nor spatiotemporally located entities exist as a part of a fundamental theory of QG, then such a theory seems to imply that there are no observables and so no way that the theory can be confirmed. The threat of empirical incoherence can be addressed by treating spacetime and spatiotemporally located entities as emergent. The question then arises as to what the metaphysical nature of this emergence might be. In this paper, I explore a functionalist approach to this kind of emergence in the context of loop quantum gravity. I begin by rehearsing the spacetime functionalist’s account of emergence, clarifying the view along the way. I proceed to sketch out a functionalist treatment of spatiotemporally located entities and combine the two forms of functionalism into a double functionalism, according to which both spacetime and matter have the same functional realisers.


Spacetime Functionalism Loop quantum gravity Quantum gravity Empirical incoherence Observation Helon 



Funding was provided by The Australian Research Council (Grant No. DE180100414), Australian Research Council (Grant No. DP180100105).


  1. Barrett, J. A. (1999). The quantum mechanics of minds and worlds. New York: Oxford University Press.Google Scholar
  2. Bilson-Thompson, S., Hackett, J., & Kauffman, L. (2009). Particle topology, braids and braided belts. Journal of Mathematical Physics, 50, 113505.CrossRefGoogle Scholar
  3. Bilson-Thompson, S., Hackett, J., Kauffman, L., & Wan, Y. (2012). Emergent braided matter of quantum geometry. SIGMA, 8, 14–47.Google Scholar
  4. Bilson-Thompson, S. O. (2005). A topological model of composite preons. arXiv:hep-ph/0503213.
  5. Bilson-Thompson, S. O., Markopolou, F., & Smolin, L. (2007). Quantum gravity and the standard model. Classical and Quantum Gravity, 24, 3975.CrossRefGoogle Scholar
  6. Butterfield, J., & Isham, C. (1999). On the emergence of time in quantum gravity. In J. Butterfield (Ed.), The arguments of time (pp. 111–168). Oxford: Oxford University Press.Google Scholar
  7. Crowther, K. (2016). Effective spacetime: Understanding emergence in effective field theory and quantum gravity. Heidelberg: Springer.CrossRefGoogle Scholar
  8. Crowther, K. (2017). Inter-theory relations in quantum gravity: Correspondence, reduction, and emergence. Studies in History and Philosophy of Modern Physics, 63, 1–12.CrossRefGoogle Scholar
  9. Hackett, J. (2007). Locality and translations in braided ribbon networks. Classical Quantum Gravity, 24, 5757–5766.CrossRefGoogle Scholar
  10. Hackett, J., & Wan, Y. (2009). Conserved quantities for interacting 4-valent braids in quantum gravity. Classical and Quantum Gravity, 26, 125008.CrossRefGoogle Scholar
  11. Harari, H. (1979). A schematic model of quarks and leptons. Physics Letters B, 86, 83–86.CrossRefGoogle Scholar
  12. Harari, H., & Seiberg, N. (1981). A dynamical theory for the rishon model. Physics Letters, 98B, 269–273.CrossRefGoogle Scholar
  13. He, S., & Wan, Y. (2008a). C, p and t of braid excitations in quantum gravity. Nuclear Physics B, 805, 1–23.CrossRefGoogle Scholar
  14. He, S., & Wan, Y. (2008b). Conserved quantities and the algebra of braid excitations in quantum gravity. Nuclear Physics B, 804, 286–306.CrossRefGoogle Scholar
  15. Huggett, N., & Wüthrich, C. (2013). Emergent spacetime and empirical (in)coherence. Studies in History and Philosophy of Modern Physics, 44, 276–285.CrossRefGoogle Scholar
  16. Knox, E. (2013). Effective spacetime geometry. Studies in History and Philosophy of Physics, 44, 346–365.CrossRefGoogle Scholar
  17. Knox, E. (2019). Physical relativity from a functionalist perspective. Studies in History and Philosophy of Modern Physics,. Scholar
  18. Lam, V., & Esfeld, M. (2013). A dilemma for the emergence of spacetime in canonical quantum gravity. Studies in History and Philosophy of Modern Physics, 44, 286–293.CrossRefGoogle Scholar
  19. Lam, V., & Wüthrich, C. (2018). Spacetime is as spacetime does. Studies in History and Philosophy of Modern Physics, 64, 39–51.CrossRefGoogle Scholar
  20. Le Bihan, B. (2016). Super-relationism: Combining eliminativism about objects and relationism about spacetime. Philosophical Studies, 173, 2151–2172.CrossRefGoogle Scholar
  21. Le Bihan, B. (2018). Space emergence in contemporary physics: Why we do not need fundamentality, layers of reality and emergence. Disputatio, 10, 71–95.CrossRefGoogle Scholar
  22. Le Bihan, B. (2018). Priority monism beyond spacetime. Metaphysica, 19(1), 95–111.CrossRefGoogle Scholar
  23. Lehmkuhl, D. (2016). The metaphysics of super-substantivalism. Noüs, 52, 2.Google Scholar
  24. Maudlin, T. (2007). Completeness, supervenience and ontology. Journal of Physics A: Mathematical and Theoretical, 40, 3151–3171.CrossRefGoogle Scholar
  25. Ney, A. (2015). Fundamental physical ontologies and the constraint of empirical coherence: A defense of wave function realism. Synthese, 192, 3105–3124.CrossRefGoogle Scholar
  26. Norton, J. D. (ms). Loop quantum ontology: spin-networks and spacetime.
  27. Oriti, D. (2014). Disappearance and emergence of space and time in quantum gravity. Studies in History and Philosophy of Modern Physics, 46, 186–199.CrossRefGoogle Scholar
  28. Pati, J. C., & Salam, A. (1974). Lepton number as the fourth “color”. Physical Review D, 10, 275.CrossRefGoogle Scholar
  29. Paul, L. A. (2002). Logical parts. Noûs, 36, 578–596.CrossRefGoogle Scholar
  30. Paul, L. A. (2012a). Building the world from its fundamental constituents. Philosophical Studies, 158, 221–256.CrossRefGoogle Scholar
  31. Paul, L. A. (2012b). Metaphysics as modeling: The handmaiden’s tale. Philosophical Studies, 160, 1–29.CrossRefGoogle Scholar
  32. Polger, T. W. (2007). Realization and the metaphysics of mind. Australasian Journal of Philosophy, 85, 233–259.CrossRefGoogle Scholar
  33. Rovelli, C. (2004). Quantum gravity. Cambridge: Cambridge University Press.CrossRefGoogle Scholar
  34. Rovelli, C. (2011). A new look at loop quantum gravity. Classical and Quantum Gravity, 28, 114005.CrossRefGoogle Scholar
  35. Schaffer, J. (2009). Spacetime the one substance. Philosophical Studies, 145, 131–148.CrossRefGoogle Scholar
  36. Shupe, M. A. (1979). A composite model of leptons and quarks. Physics Letters B, 1, 87–92.CrossRefGoogle Scholar
  37. Smolin, L., & Wan, Y. (2008). Propogation and interaction of chiral states in quantum gravity. Nuclear Physics B, 796, 331–359.CrossRefGoogle Scholar
  38. Wan, Y. (2009). Effective theory of braid excitations of quantum gravity in terms of Feynman diagrams. Nuclear Physics B, 814, 1–20.CrossRefGoogle Scholar
  39. Wüthrich, C. (2017). Raiders of the lost spacetime. In D. Lehmkuhl, G. Schiemann, & E. Scholz (Eds.), Towards a theory of spacetime theories. Birkhäuser: Basal.Google Scholar
  40. Wüthrich, C. (2019). The emergence of space and time. In S. Gibb, R. F. Hendry, & T. Lancaster (Eds.), Routledge handbook of emergence. London: Routledge.Google Scholar
  41. Yates, D. (forthcoming). Thinking about spacetime. In C. Wüthrich, B. Le Bihan, & N. Huggett (Eds.), Philosophy beyond spacetime. Oxford: Oxford University Press. Google Scholar

Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.Department of Philosophy, School of HumanitiesUniversity of Western AustraliaCrawleyAustralia

Personalised recommendations