, Volume 184, Issue 3, pp 387–405 | Cite as

A computer simulation of the argument from disagreement

  • Johan E. Gustafsson
  • Martin Peterson
Open Access


In this paper we shed new light on the Argument from Disagreement by putting it to test in a computer simulation. According to this argument widespread and persistent disagreement on ethical issues indicates that our moral opinions are not influenced by any moral facts, either because no such facts exist or because they are epistemically inaccessible or inefficacious for some other reason. Our simulation shows that if our moral opinions were influenced at least a little bit by moral facts, we would quickly have reached consensus, even if our moral opinions were affected by factors such as false authorities, external political shifts, and random processes. Therefore, since no such consensus has been reached, the simulation gives us increased reason to take seriously the Argument from Disagreement. Our conclusion is however not conclusive; the simulation also indicates what assumptions one has to make in order to reject the Argument from Disagreement. The simulation algorithm we use builds on the work of Hegselmann and Krause (J Artif Soc Social Simul 5(3); 2002, J Artif Soc Social Simul 9(3), 2006).


Hegselmann–Krause Disagreement Simulation Meta-ethics Moral realism Opinion dynamics 



Early versions of this paper were presented to audiences at conferences and seminars at the University of Colorado at Boulder, Stockholm University, Uppsala University, Lund University, Luleå University of Technology, Delft University of Technology, and the Buenos Aires Metaethics Workshop. We would like to thank the participants for very helpful comments. We also wish to thank two anonymous reviewers for equally helpful comments.

Open Access

This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.


  1. Boyd R. N. (1988) How to be a moral realist. In: Sayre-McCord G. (eds) Essays on moral realism. Cornell University Press, Ithaca, NY, pp 181–228Google Scholar
  2. Brink D. O. (1989) Moral realism and the foundations of ethics. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  3. Hartmann N. (1932) Ethics. George Allen & Unwin Ltd, LondonGoogle Scholar
  4. Hegselmann R., Krause U. (2002) Opinion dynamics and bounded confidence models, analysis, and simulation. Journal of Artifical Societies and Social Simulation 5(3): 1–33Google Scholar
  5. Hegselmann R., Krause U. (2006) Truth and cognitive division of labour: First steps towards a computer aided social epistemology. Journal of Artificial Societies and Social Simulation 9(3): 1–28Google Scholar
  6. Krause U. (2008) Compromise, consensus and the iteration of means. Elemente der Mathematik 63: 1–8Google Scholar
  7. Lorenz, J. (2007). Repeated averaging and bounded confidence modeling, analysis and simulation of continuous opinion dynamics. PhD thesis, Universität Bremen.Google Scholar
  8. Lorenz, J., & Lorenz, D. A. (2008) On conditions for convergence to consensus. Arxiv preprint arXiv:08032211.Google Scholar
  9. Mackie J. L. (1977) Ethics: Inventing right and wrong. Penguin, HarmondsworthGoogle Scholar
  10. Shafer-Landau R. (2003) Moral realism: A defence. Oxford University Press, OxfordCrossRefGoogle Scholar
  11. Sturgeon N. L. (1985) Moral explanations. In: Copp D., Zimmerman D. (eds) Morality, reason, and truth: New essays on the foundations of ethics. Rowman & Allanheld, Totowa, pp 49–78Google Scholar
  12. Tersman F. (2006) Moral disagreement. Cambridge University Press, CambridgeCrossRefGoogle Scholar

Copyright information

© The Author(s) 2010

Authors and Affiliations

  1. 1.Division of PhilosophyRoyal Institute of TechnologyStockholmSweden
  2. 2.Section for Philosophy and EthicsEindhoven University of TechnologyEindhovenThe Netherlands

Personalised recommendations