•  18
    Legal Consciousness and the Internal Aspect of Rules
    In Jakob V. H. Holtermann, Mario Kresić & Marko Novak (eds.), Legal Consciousness, Springer Nature Switzerland. pp. 201-222. 2025.
    This contribution starts from the assumption that law exists in legal consciousness, that is: in the beliefs and attitudes of people who jointly guide their lives by law. It aims to give an account of legal consciousness that combines Haidt’s ideas about the origin of moral judgements, Berger and Luckman’s ideas about the social origin of knowledge (very loosely), and Popper’s idea that scientific knowledge is a collective product (epistemology without a knowing subject). According to Haidt, (mo…Read more
  •  12
    Of Norms
    In Giorgio Bongiovanni, Gerald Postema, Antonino Rotolo, Giovanni Sartor, Chiara Valentini & Douglas Walton (eds.), Handbook of Legal Reasoning and Argumentation, Imprint: Springer. pp. 103-138. 2018.
    This contribution elaborates the idea that norms are rules that lead to deontic consequences. Rules are one kind of constraints on possible worlds. They determine which facts necessarily go together or cannot go together. Three kinds of rules are distinguished: dynamic rules which attach consequences to the occurrence of events, fact-to-fact rules which attach one fact to the presence of some other fact, and counts-as rules, which make that some things (often events) also count as something else…Read more
  •  21
    Introduction to Law (edited book)
    with Bram Akkermans
    Imprint: Springer. 2014.
    This book is exceptional in the sense that it provides an introduction to law in general rather than the law of one specific jurisdiction, and it presents a unique way of looking at legal education. It is crucial for lawyers to be aware of the different ways in which societal problems can be solved and to be able to discuss the advantages and disadvantages of different legal solutions. In this respect, being a lawyer involves being able to reason like a lawyer, even more than having detailed kno…Read more
  •  36
    Juridical Acts and the Gap between Is and Ought
    Netherlands Journal of Legal Philosophy 42 (1): 50-66. 2013.
    Juridical Acts and the Gap between Is and Ought This article addresses the possibility of deriving ought from is. To that purpose it casts doubt on the very distinction between is and ought; distinguishes between duties, obligations, being obligated and owing to do something; revitalises Searle’s famous derivation of ought from is by replacing promises with contracts; and discusses some of the traditional objections against this derivation. The conclusions are that it is not problematic at all t…Read more
  • Constitutivism and Social Reality
    In Stefano Bertea & Jorge Silva Sampaio (eds.), Metaethical issues in contemporary legal philosophy: a constitutivist approach, Routledge, Taylor & Francis Group. 2025.
  •  61
    How Law’s Nature Influences Law’s Logic
    Studia Humana 13 (3): 4-17. 2024.
    Classical logic is based on an underlying view of the world, according to which there are elementary facts and compound facts, which are logical combinations of these elementary facts. Sentences are true if they correspond to, in last instance, the elementary facts in the world. This world view has no place for rules, which exist as individuals in the world, and which create relations between the most elementary facts. As a result, classical logic is not suitable to deal with rules, and is there…Read more
  • Objectivity of law and objectivity about law
    In Gonzalo Villa Rosas & Jorge Luis Fabra-Zamora (eds.), Objectivity in jurisprudence, legal interpretation and practical reasoning, Edward Elgar Publishing. 2022.
  •  96
    Legal Validity and Soft Law (edited book)
    with Anne Mackor, Stephan Kirste, and Pauline Westerman
    Springer Verlag. 2018.
    This book features essays that investigate the nature of legal validity from the point of view of different traditions and disciplines. Validity is a fascinating and elusive characteristic of law that in itself deserves to be explored, but further investigation is made more acute and necessary by the production, nowadays, of soft law products of regulation, such as declarations, self-regulatory codes, and standardization norms. These types of rules may not exhibit the characteristics of formal l…Read more
  •  25
    Introduction to Law (edited book)
    with Bram Akkermans and Antonia Waltermann
    Imprint: Springer. 2017.
    This book is exceptional in the sense that it provides an introduction to law in general rather than the law of one specific jurisdiction, and it presents a unique way of looking at legal education. It is crucial for lawyers to be aware of the different ways in which societal problems can be solved and to be able to discuss the advantages and disadvantages of different legal solutions. In this respect, being a lawyer involves being able to reason like a lawyer, even more than having detailed kno…Read more
  •  120
    Constructivist Facts as the Bridge Between Is and Ought
    International Journal for the Semiotics of Law - Revue Internationale de Sémiotique Juridique 36 (1): 53-81. 2022.
    This article describes how the facts in social reality take an intermediate position between objective facts and purely subjective ‘facts’. In turn, these social facts can be subdivided into constructivist and non-constructivist facts. The defining difference is that non-constructivist facts are completely determined by an approximate consensus between the members of a social group, while constructivist facts are founded in such a consensus but can nevertheless be questioned. Ought fact are such…Read more
  •  48
    Law and Mind: A Survey of Law and the Cognitive Sciences (edited book)
    with Bartosz Brożek and Nicole Vincent
    Cambridge University Press. 2021.
    Are the cognitive sciences relevant for law? How do they influence legal theory and practice? Should lawyers become part-time cognitive scientists? The recent advances in the cognitive sciences have reshaped our conceptions of human decision-making and behavior. Many claim, for instance, that we can no longer view ourselves as purely rational agents equipped with free will. This change is vitally important for lawyers, who are forced to rethink the foundations of their theories and the framework…Read more
  •  42
    Of Norms
    In Giorgio Bongiovanni, Gerald Postema, Antonino Rotolo, Giovanni Sartor, Chiara Valentini & Douglas Walton (eds.), Handbook of Legal Reasoning and Argumentation, Springer. pp. 103-138. 2011.
    This contribution elaborates the idea that norms are rules that lead to deontic consequences. Rules are one kind of constraints on possible worlds. They determine which facts necessarily go together or cannot go together. Three kinds of rules are distinguished: dynamic rules which attach consequences to the occurrence of events, fact-to-fact rules which attach one fact to the presence of some other fact, and counts-as rules, which make that some things also count as something else. Deontic facts…Read more
  •  36
    The Limited Function of Hermeneutics in Law
    In David Duarte, Pedro Moniz Lopes & Jorge Silva Sampaio (eds.), Legal Interpretation and Scientific Knowledge, Springer Verlag. pp. 1-11. 2019.
    My main claim in this article is that lawyers should make less use of the hermeneutical method than they do. The reasons that I will adduce to support this claim are the following: law is first and foremost an answer to the question of how to act and, more in particular, the question of which rules to enforce by collective means. As such, law does not coincide with positive law. Nevertheless, positive law determines the content of the law to a large extent. It does so for two reasons. The first …Read more
  •  35
    What Is Legal Validity? Lessons from Soft Law
    In Anne Mackor, Stephan Kirste, Jaap Hage & Pauline Westerman (eds.), Legal Validity and Soft Law, Springer Verlag. pp. 19-45. 2018.
    The purpose of this article is to use the elusive phenomena of legal validity and soft law to illuminate each other. Three notions of legal validity are distinguished. Source validity and binding force (in a special technical sense) are internal legal notions that are used in legal argumentation. On the contrary, efficacy (also in a special technical sense) is an external notion, used in descriptive theories about law such as sociology of law or legal theory. Source validity is a characteristic …Read more
  • Rechtsfilosofische annotaties: HR 26 januari 1990, NJ 1990, 794
    Netherlands Journal of Legal Philosophy 2 197-203. 2004.
  • Jurisprudence or Legal Science? (review)
    Netherlands Journal of Legal Philosophy 2 207-210. 2006.
  • Kunstige filosofie
    Netherlands Journal of Legal Philosophy 2 64-67. 2007.
  • The Objectivity of Value Judgements
    Rechtstheorie 17 (4): 501-507. 1986.
  •  102
    An integrated view on rules and principles
    with Bart Verheij and H. Jaap Van Den Herik
    Artificial Intelligence and Law 6 (1): 3-26. 1998.
    In the law, it is generally acknowledged that there are intuitive differences between reasoning with rules and reasoning with principles. For instance, a rule seems to lead directly to its conclusion if its condition is satisfied, while a principle seems to lead merely to a reason for its conclusion. However, the implications of these intuitive differences for the logical status of rules and principles remain controversial.A radical opinion has been put forward by Dworkin (1978). The intuitive d…Read more
  •  248
    Hard cases: A procedural approach (review)
    with Ronald Leenes and Arno R. Lodder
    Artificial Intelligence and Law 2 (2): 113-167. 1993.
    Much work on legal knowledge systems treats legal reasoning as arguments that lead from a description of the law and the facts of a case, to the legal conclusion for the case. The reasoning steps of the inference engine parallel the logical steps by means of which the legal conclusion is derived from the factual and legal premises. In short, the relation between the input and the output of a legal inference engine is a logical one. The truth of the conclusion only depends on the premises, and is…Read more
  •  29
    Recht als sociaal feit en recht als praktische rede
    Netherlands Journal of Legal Philosophy 38 (1): 27-36. 2009.
    Brouwer argued against a vision of the law in which moral considerations partly determine the contents of the law. He did this for moral reasons, mainly because of the uncertainty such a vision would cause. This seems a strange view because it means that the nature of the law would depend on moral considerations concerning legal certainty. Most of the present paper is devoted to exploring two conceptions of the law, law as social fact and law as practical reason. It is argued that a view like Br…Read more
  •  63
    The Logic of Analogy in the Law
    Argumentation 19 (4): 401-415. 2005.
    This paper deals with two issues in the field of reasoning by analogy in the law. The one issue is whether there exists such a thing as analogous rule application, or whether there is only the ‘normal’ application of a broadened rule. It is argued that if rules, as the entities made by a legislator, are distinguished from generalised solutions for cases, the idea of analogous application of rules makes sense. It is also shown how the so-called ‘reason-based model of rule application’, in contras…Read more
  • In memoriam: Popke Wieger Brouwer
    Netherlands Journal of Legal Philosophy 3 213-214. 2006.
  • Legal transactions and the legal ought
    In Jerzy Stelmach & Bartosz Brożek (eds.), The normativity of law, Copernicus Center Press. 2011.
  •  130
    Donald NUTE (ed.), Defeasible deontic logic
    Artificial Intelligence and Law 8 (1): 75-91. 2000.
  •  84
    Rule-applying legal arguments are traditionally treated as a kind of syllogism. Such a treatment overlooks the fact that legal principles and rules are not statements which describe the world, but rather means by which humans impose structure on the world. Legal rules create legal consequences, they do not describe them. This has consequences for the logic of rule- and principle-applying arguments, the most important of which may be that such arguments are defeasible. This book offers an extensi…Read more
  •  90
    Law and Coherence
    Ratio Juris 17 (1): 87-105. 2004.
    This paper deals with the questions of whether the law should be coherent and what this coherence would amount to. In this connection so‐called “integrated coherentism” is introduced. According to integrated coherentism, an acceptance set is coherent if and only if it contains everything that should rationally be accepted according to what else one accepts and does not contain anything that should rationally be rejected according to what else one accepts. Such an acceptance set is ideally a theo…Read more
  • De betekenis van juridische statuswoorden
    Netherlands Journal of Legal Philosophy 37 (1): 13-28. 2008.