Lex Minus Dixit Quam Voluit, Lex Magis Dixit Quam Voluit: A Formal Study on Legal Compliance and Interpretation

  • Guido Boella
  • Guido Governatori
  • Antonino Rotolo
  • Leendert van der Torre
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6237)


This paper argues in favour of the necessity of dynamically restricting and expanding the applicability of norms regulating computer systems like multiagent systems, in situations where the compliance to the norm does not achieve the purpose of the norm. We propose a logical framework which distinguishes between constitutive and regulative norms and captures the norm change power and at the same time the limitations of the judicial system in dynamically revising the set of constitutive rules defining the concepts on which the applicability of norms is based. In particular, the framework is used to reconstruct some interpretive arguments described in legal theory such as those corresponding to the Roman maxims lex minus dixit quam voluit and lex magis dixit quam voluit. The logical framework is based on an extension of defeasible logic.


Multiagent System Normative Theory Legal Rule Constitutive Rule Legal Concept 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. 1.
    Antoniou, G., Billington, D., Governatori, G., Maher, M.J.: Representation results for defeasible logic. ACM Trans. Comput. Log. 2(2), 255–287 (2001)CrossRefGoogle Scholar
  2. 2.
    Bench-Capon, T.J.M.: The missing link revisited: The role of teleology in representing legal argument. Artif. Intell. Law 10(1-3), 79–94 (2002)CrossRefGoogle Scholar
  3. 3.
    Billington, D., Antoniou, G., Governatori, G., Maher, M.J.: Revising nonmonotonic belief sets: The case of defeasible logic. In: Burgard, W., Christaller, T., Cremers, A.B. (eds.) KI 1999. LNCS (LNAI), vol. 1701, pp. 101–112. Springer, Heidelberg (1999)CrossRefGoogle Scholar
  4. 4.
    Boella, G., van der Torre, L.: Fulfilling or violating obligations in multiagent systems. In: Procs. IAT 2004 (2004)Google Scholar
  5. 5.
    Boella, G., van der Torre, L.: Norm negotiation in multiagent systems. Int. Journal Coop. Inf. Syst. 16(1), 97–122 (2007)CrossRefGoogle Scholar
  6. 6.
    Casanovas, P. (ed.): Proc. LOAIT 2007. CEUR (2008)Google Scholar
  7. 7.
    Ginsberg, M.L.: Universal planning: An (almost) universally bad idea. AI Magazine 10(4), 40–44 (1989)Google Scholar
  8. 8.
    Governatori, G., Maher, M.J., Billington, D., Antoniou, G.: Argumentation semantics for defeasible logics. Journal of Logic and Computation 14, 675–702 (2004)CrossRefGoogle Scholar
  9. 9.
    Governatori, G., Olivieri, F., Scannapieco, S., Cristani, M.: Superiority based revision of defeasible theories. In: Proc. NMR 2010. CUER (2010)Google Scholar
  10. 10.
    Governatori, G., Rotolo, A.: BIO logical agents: Norms, beliefs, intentions in defeasible logic. Autonomous Agents and Multi-Agent Systems 17(1), 36–69 (2008)CrossRefGoogle Scholar
  11. 11.
    Governatori, G., Rotolo, A.: A computational framework for institutional agency. Artif. Intell. Law 16(1), 25–52 (2008)CrossRefGoogle Scholar
  12. 12.
    Governatori, G., Rotolo, A., Sartor, G.: Temporalised normative positions in defeasible logic. In: Proc. ICAIL 2005, pp. 25–34. ACM, New York (2005)Google Scholar
  13. 13.
    Grossi, D.: Desigining Invisible Hancuffs. Formal Investigations in Institutions and Organizations for Multi-Agent Systems. PhD thesis, Utrecht University (2007)Google Scholar
  14. 14.
    Hage, J.: Reasoning with Rules: An Essay on Legal Reasoning and Its Underlying Logic. Kluwer, Dordrecht (1997)CrossRefGoogle Scholar
  15. 15.
    Hart, H.L.A.: Positivism and the separation of law and morals. Harvard Law Review 71(4), 593–629 (1958)CrossRefGoogle Scholar
  16. 16.
    Peczenik, A.: On law and reason. Kluwer, Dordrecht (1989)CrossRefGoogle Scholar
  17. 17.
    Prakken, H.: An exercise in formalising teleological case-based reasoning. Artif. Intell. Law 10, 113–133 (2002)CrossRefGoogle Scholar
  18. 18.
    Sartor, G.: Legal reasoning: A cognitive approach to the law. Springer, Dordrecht (2005)Google Scholar
  19. 19.
    Sartor, G.: Fundamental legal concepts: A formal and teleological characterisation. Artif. Intell. Law 14(1-2), 101–142 (2006)CrossRefGoogle Scholar
  20. 20.
    Searle, J.R.: The Construction of Social Reality. The Free Press, New York (1995)Google Scholar
  21. 21.
    Skalak, D.B., Rissland, E.L.: Arguments and cases: An inevitable intertwining. Artif. Intell. Law 1, 3–44 (1992)CrossRefGoogle Scholar
  22. 22.
    van der Torre, L., Boella, G., Verhagen, H. (eds.): Normative Multi-agent Systems. Special Issue of JAAMAS, vol. 17(1) (2008)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Guido Boella
    • 1
  • Guido Governatori
    • 2
  • Antonino Rotolo
    • 3
  • Leendert van der Torre
    • 4
  1. 1.University of TurinItaly
  2. 2.NICTAAustralia
  3. 3.University of BolognaItaly
  4. 4.University of LuxembourgLuxembourg

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