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A system of communication rules for justifying and explaining beliefs about facts in civil trials

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This paper addresses the problems of justifying and explaining beliefs about facts in the context of civil trials. The first section contains some remarks about the nature of adjudicative fact-finding and highlights the communicative features of deciding about facts in judicial context. In Sect. 2, some difficulties and the incompleteness presented by Bayesian and coherentist frameworks, which are taken as methods suitable to solve the above-mentioned problems, are pointed out. In the third section, the purely epistemic approach to the justification and the explanation of beliefs about facts is abandoned and focus is given to the dialectical nature of civil procedure, where the parties and, particularly, the judge have to make their reasoning clear enough to allow a fruitful and efficient debate about facts. For this purpose, a communication/argumentation system is put forward, consisting of fourteen intertwined rules of discourse. The system embodies the fundamental epistemic principle according to which belief is updated given new evidence, is tailored for abductive inferences and is structured on fundamental concepts of civil procedural law. The fourth section presents an empirical application of the system to a real case.

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  1. Nor it is in criminal trials; but it is not the aim of this paper to debate that.

  2. It is important to distinguish the role of "communication" in the ideas put forward in this paper from the one the same concept/act plays in some theories of legal punishment [in this respect see, e.g., Duff (2001)]. Whereas in these later "communication" is seen as a consequence or a feature of punishment, in other words, punishment is a tool to communicate to offenders the censure deserved for their wrongdoing, and therefore we can talk of "moral communication" for legal purposes; in this paper it will be argued that the judge has to explain, communicate, to the parties the intellectual path he followed in considering proven or not proven the facts, and therefore we may talk of "epistemic communication" for legal purposes.

  3. Though the problems referred in text are perhaps the most relevant for the purpose of this paper, others are usually pointed out by the relevant literature: (1) the problem of reference classes, extensively analysed and exemplified by Allen and Pardo (2007, 111ff.); (2) the conjunction paradox, particularly significant in civil cases, which was firstly identified by Cohen (1977, 58ff.); (3) the prior probabilities problem, clearly stated, for instance, by Friedman (2000) and Finkelstein (2009, 11ff.). Allen (2017), though reiterating some of the above-mentioned obstacles, makes interesting considerations about the (limited) possibilities of integrating probability calculus into legal fact-finding.

  4. These are, notwithstanding, only two among various obstacles coherence faces. Some of them could be labelled as theoretical problems, such as (1) the undefined nature of coherence or (2) the doubts about the relation of coherence with truth (for instance: if we favour a theory of correspondence for truth in legal context, how will it cohabitate with epistemic coherence?). Other problems are more practical, as for instance the so-called isolation objection, and sometimes quite worrisome in the context of adjudicative fact-finding: e.g., one may be entitled to ask whether putting coherence at the centre of reasoning about evidence triggers our perhaps natural tendency to interpret the evidence in accordance with previous beliefs, that is to say, to force the available evidence to cohere with the narrative that seems more plausible according to those previous beliefs [see e.g. Taruffo (2007)].

  5. Besides other more technical or procedural problems. For instance, Amaya (2013, 26) states the following: "(…) fact finders are expected to seek out the evidence necessary to find out about the events at trial.". At least for civil trials, many Legal Orders restrict judge's initiative towards obtaining new evidence; the parties present the evidence with which they intend to prove their case; the judge is allowed to do little more then decide if (and why) they were successful.

  6. Within the context of plausible reasoning and argumentative approach to adjudicative fact-finding the relevance of IBE has been stressed, e.g., by Pardo and Allen (2008) and Allen and Stein (2013, 567–571). And it is important to have in mind that not only those who enhance the argumentative nature of judicial reasoning about evidence confer a prominent role to IBE. The above–mentioned coherentist approach rests its operability on this kind of inference [in particular, see Amaya (2009)]. Simultaneously, it goes on a vivid debate in epistemology about the possibility of conciliating bayesianism with IBE: for instance Lipton (2004, 106–107) even declared that "(…) not only(…) Bayes' theorem and explanationism are compatible, but (…) they are complementary.".

  7. It is up to the judge to decide and explain why a certain witness is credible or not. Some facts about her/him and some features of her/his testimony may work as clues for the purpose of assessing credibility.

  8. An example would be useful, in case the irrelevance of the evidence described in (2) and (3) is not clear. Let us say α is walking in open land when it starts raining. What is the probability of α becoming wet? Assuming he may take shelter in a hut at a distance of 300 m., we would say the probability is ≈ 0,8. And what is the probability of α becoming wet, given he was not carrying an umbrella? ≈ 0,8. i.e., the evidence for the non-occurrence of certain facts is irrelevant to the creation of a belief epistemically based on an event that has taken place. However, it shall not be forgotten that the Law is sometimes interested in knowing if the positive counterfactual would or would have not decreased the probability of said event taking place.


  • Allen RJ (2017) The nature of juridical proof: probability as a tool in plausible reasoning. Int J Evid Proof 21(1–2):133–142

    Article  Google Scholar 

  • Allen RJ, Pardo MS (2007) The problematic value of mathematical models of evidence. J Legal Stud 36(1):107–140

    Article  Google Scholar 

  • Allen RJ, Stein A (2013) Evidence, probability, and the burden of proof. Ariz Law Rev 55(3):557–602

    Google Scholar 

  • Amaya A (2009) Inference to the best legal explanation. In: Kaptein H (ed) Legal evidence and proof: statistics, stories, logic. Ashgate Publishing, Farnham

    Google Scholar 

  • Amaya A (2013) Coherence, evidence and legal proof. Legal Theory 19(1):1–43

    Article  Google Scholar 

  • Bex F (2015) An integrated theory of causal stories and evidential arguments. In: Proceedings of the 15th international conference on artificial intelligence and law. pp 13–22

  • Cohen LJ (1977) The probable and the provable. Oxford University Press, Oxford

    Book  Google Scholar 

  • Duff RA (2001) Punishment, communication, and community. Oxford University Press, Oxford

    Google Scholar 

  • Fenton N, Neil M (2013) Risk assessment and decision analysis with bayesian networks. CRC Press, Boca Raton

    MATH  Google Scholar 

  • Finkelstein MO (2009) Basic concepts of probability and statistics in the law. Springer, Berlin

    Book  Google Scholar 

  • Friedman RD (2000) A presumption of innocence, not of even odds. Stanf Law Rev 52:873–887

    Article  Google Scholar 

  • Hill B (2013) Confidence and decision. Games Econ Behav 82:675–692

    Article  MathSciNet  Google Scholar 

  • Jackson BS (1988) Law, fact and narrative coherence. Deborah Charles Publications, Liverpool

    Google Scholar 

  • Keppens J (2016) Explaining Bayesian belief revision for legal applications. Legal Knowl Inf Syst 294:63–72

    Google Scholar 

  • Lipton P (2004) Inference to the best explanation. Routledge, Abingdon

    Google Scholar 

  • Pardo MS, Allen RJ (2008) Juridical proof and the best explanation. Law Philos 27(3):223–268

    Article  Google Scholar 

  • Schum DA (1999) Inference networks and the evaluation of evidence: alternative analyses. In: Proceedings of the fifteenth conference on uncertainty in artificial intelligence, pp 575–584

  • Taruffo M (2007) Narrativas Judiciales. Revista de Derecho (Valdivia) 20(1):231–270

    Article  Google Scholar 

  • Thagard P (1989) Explanatory coherence. Behav Brain Sci 12(3):435–502

    Article  Google Scholar 

  • Thagard P (2004) Causal inference in legal decision making: explanatory coherence vs bayesian networks. Appl Artif Intell 18:231–249

    Article  Google Scholar 

  • Thagard P (2005) Testimony, credibility and explanatory coherence. Erkenntnis 63:295–316

    Article  Google Scholar 

  • Verheij B (2017) Proof with and without probabilities. Artif Intell Law 25:127–154

    Article  Google Scholar 

  • Vlek CS, Prakken H, Renooij S, Verheij B (2014) Building Bayesian networks for legal evidence with narratives: a case study evaluation. Artif Intell Law 22:375–421

    Article  Google Scholar 

  • Wigmore JH (1913) The principles of juridical proof. Little, Brown and Company, Boston

    Google Scholar 

Download references

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Correspondence to João Marques Martins.

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I am in debt to the anonymous referees, Marcello di Bello and Bart Verheij for the insightful comments and suggestions on earlier versions of this paper.

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Marques Martins, J. A system of communication rules for justifying and explaining beliefs about facts in civil trials. Artif Intell Law 28, 135–150 (2020).

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