Dr Hrafn Asgeirsson

Reader in Philosophy and Law
Ph.D. (University of Southern California)
+44 (0)1483 682854
30 AB 05

Academic and research departments

School of Law.



Dr Hrafn Asgeirsson (PhD, USC) joined the School of Law in 2016, as Senior Lecturer (Associate Professor), now Reader, in Philosophy and Law and member of the Surrey Centre for Law and Philosophy. Prior to that, Dr Asgeirsson was Postdoctoral Research Fellow at the University of Iceland, and before that Postdoctoral Research Fellow at Monash University, Faculty of Law. In 2015, he was H.L.A. Hart Visiting Fellow at the Oxford Centre for Ethics and Philosophy of Law. Dr Asgeirsson is the author of The Nature and Value of Vagueness in the Law (Hart Publishing).

Research interests

Dr Asgeirsson's main interests lie in philosophy of law, philosophy of language, and metaethics - he welcomes enquires from students seeking supervision on topics in his areas of research, including:

  • General jurisprudence; philosophical theories about the nature of law
  • Law and language; constitutional and statutory interpretation
  • Legal normativity; the legitimacy/authority of law; legal obligation


  • Jurisprudence
  • Law and Contemporary Social Issues
  • Tort

Departmental duties

Co-Director, Surrey Centre for Law and Philosophy; Director of PhD admissions


Surrey Centre for Law and Philosophy


HRAFN ASGEIRSSON (2019)The Sorites Paradox in Practical Philosophy, In: Sergi Oms, Elia Zardini (eds.), The Sorites Paradoxpp. 229-245 Cambridge University Press

The first part of the chapter surveys some of the main ways in which the Sorites Paradox has figured in arguments in practical philosophy in recent decades, with special attention to arguments where the paradox is used as a basis for criticism. Not coincidentally, the relevant arguments all involve the transitivity of value in some way. The second part of the chapter is more probative, focusing on two main themes. First, it further addresses the relationship between the Sorites Paradox and the main arguments discussed in the first part, by elucidating in what sense they rely on (something like) tolerance principles. Second, it briefly discusses the prospect of rejecting the respective principles, aiming to show that we can do so for some of the arguments but not for others. The reason is that in the latter cases the principles do not function as independent premises in the reasoning but, rather, follow from certain fundamental features of the relevant scenarios. It is also argued that not even adopting what is arguably the most radical way to block the Sorites Paradox – that of weakening the consequence relation – suffices to invalidate these arguments.

H Asgeirsson (2015)On the Instrumental Value of Vagueness in the Law, In: Ethics125(2)pp. 425-448 The University of Chicago Press

It is natural to think that law ought not to be vague. After all, law is supposed to guide conduct, and vague law seems poorly suited to do that. Contrary to this common impression, however, a number of authors have argued that vagueness in the law is sometimes a good thing, because it is a means to achieving certain valuable legislative ends. In this article, I argue that many authors—including Timothy Endicott and Jeremy Waldron—wrongly associate vagueness with instrumental roles that are really played by a closely related semantic phenomenon.

H Asgeirsson (2016)On the Possibility of Non-literal Legislative Speech, In: Pragmatics and Law10 Springer International Publishing

The existing literature on indeterminacy in the law focuses mostly on the use of vague terms in legislation – terms the use of which makes the content of the relevant utterance to some extent indeterminate. As I aim to show, however, not only is the content of a legislative utterance often indeterminate, it is often indeterminate what the content of such an utterance is. In the second and third section of the chapter, I discuss in some detail the conditions for successful non-literal speech and address the question whether these conditions are satisfied in the legal context. I argue that due to the fact that legislative contexts generally contain little unequivocal information about legislative intent, interpreters are typically not warranted in taking the legislature to have intended to communicate something non-literal. In the fourth section, I consider what I take to be the strongest case against my argument: the wealth of actual cases in which the courts have taken the content of the law to be something other than its literal content, seemingly based on relatively straightforward inferences about the legislature’s communicative intentions. As I hope to show, however, very few of these cases are as straightforward as they appear to be. In the fifth, and final section, I argue that the argument from sections two and three has important consequences for the extent to which we should take the content of the law to be determinate. This has significant implications for the analysis of a number of important but controversial legal cases, which I discuss in some detail.

Textualist and originalist legal reasoning usually involves something like the following thesis, whether implicitly or explicitly: the legal content of a statute or constitutional clause is the linguistic content that a reasonable member of the relevant audience would, knowing the context and conversational background, associate with the enactment. In this paper, I elucidate some important aspects of this thesis, emphasizing the important role that contextual enrichment plays in textualist and originalist legal reasoning. The aim is to show how the linguistic framework underlying sophisticated versions of new textualism and public-meaning originalism can help to shed important light on the plausibility of what John Perry calls conception textualism. Contra Perry, I do not think that conception textualism—arguably best classified as a version of expected-applications originalism—is “confused, implausible, and unworkable.” I also briefly compare my linguistic case for conception textualism with Justice Scalia's nonlinguistic argument for it, the main premise of which concerns the constitutive function of constitutions.

HRAFN ASGEIRSSON (2022)A Puzzle About Vagueness, Reasons, and Judicial Discretion, In: Legal theory Cambridge University Press
H Asgeirsson (2012)Vagueness, Comparative Value, and the "Lawmakers’ Challenge", In: Archiv für Rechts- und Sozialphilosphie98(3)pp. 299-316 Franz Steiner Verlag

In "The Value of Vagueness," Timothy Endicott argues that vague law can be better than precise law. I think he is in many respects correct, but will suggest that we modify and supplement his framework in order to get a firmer grip on what I call the Lawmakers' Challenge: the scenario in which lawmakers find themselves when they must determine whether the consequences of precision are worse than the consequences of vagueness. This will allow us to identify several points of actual and possible disagreement regarding the value of vagueness for law, each of which could affect Endicott's claim that vagueness is sometimes preferable to precision. The framework will also allow us to compare positions that seem – on the face of it – hard to compare, due to the fact that they rest on different theories of value and/or different theories of law.

H Asgeirsson (2015)From the Nature of Things to Nature Itself: The Philosophy of Ólafur Páll Jónsson, In: G Malenfant, J Dagsson (eds.), Inquiring into Contemporary Icelandic Philosophy University of Iceland Press
H Asgeirsson (2016)Can Legal Practice Adjudicate Between Theories of Vagueness?, In: G Keil, R Poscher (eds.), Vagueness and Law: Philosophical and Legal Perspectives(4)pp. 95-126 Oxford University Press

Scott Soames has recently argued that the fact that lawmakers and other legal practitioners regard vagueness as having a valuable power-delegating function in the law, evidenced by actual legislative practice, gives us good reason to favor one theory of vagueness – the partialdefinition/ context-sensitive theory – over another – the epistemic theory. The reason, Soames says, is that for a significant set of cases, the former helps explain this function, whereas the latter does not. If Soames is right, then facts about legal practice can in an important sense adjudicate between rival theories of vagueness, which is an exciting conclusion, both from the point of view of philosophy of law and philosophy of language. The argument is also likely to generate considerable optimism about what else we might expect to learn about language by looking at the law. The purpose of this paper is to significantly temper any such expectations, by arguing that we have to give up the one premise of Soames’s argument that he seems to take to be uncontroversial: that the legal content of a statute or constitutional clause is identical with, or constituted by, its communicative content. Following Mark Greenberg, we can call this a version of the communicative-content theory of law. Recently, the communicative-content theory has come under serious pressure from several prominent philosophers of law and legal scholars – including Greenberg, Lawrence Solum, and Dale Smith – who point out that legal textbooks are full of examples in which there appears to be some clear difference between the communicative content of a statute or constitutional clause and its legal content. I argue that the problem raised by these examples gives us good reason to reject identity- and constitution-based version of the theory, like Soames’s, but go on to provide a preliminary sketch of my own account of legal content – the Pro Tanto view, as I call it – and show how it avoids the problem by allowing us to explain away the apparent “gaps” in a principled and unified way. Despite being a version of the communicative-content theory of law, however, the Pro Tanto view does not suffice to vindicate Soames’s argument for the partialdefinition/ context-sensitive theory of vagueness, which I examine in some detail in the latter half of the paper. Due to the need for a fairly complex account of the relationship between communicative content and legal content, facts about legal practice do not, after all, seem to be able to adjudicate between rival theories of vagueness – at least not in the way envisioned by Soames. Discussing, briefly, the cases of Maurice v. Judd and Bronston v. United States, I conclude by arguing that my point about Soames’s argument is generalizable: since legal content is neither identical with nor constituted by communicative content, we should be quite cautious about drawing general conclusions about language on the basis of facts about legal practice.

H Asgeirsson (2013)Vagueness and Power-Delegation in Law: A Reply to Sorensen, In: M Freeman, F Smith (eds.), Law and Language15(20)pp. 344-355 Oxford University Press

Roy Sorensen has argued that vagueness in the law cannot be justified by appeal to the value of power-delegation, and thereby threatens to take away one of the main reasons for thinking that vagueness can be valuable to law. Delegation of power to officials is justified, he thinks, only if these officials are in a better position to discover whether a particular x is F, a condition not satisfied in cases of vagueness. I argue that Sorensen’s argument is unsound: delegation of power can be valuable even if the delegates are not in a better position to answer that question.

Hrafn Ásgeirsson (2020)The nature and value of vagueness in the law Hart Publishing

"Lawmaking is - paradigmatically - a type of speech act: people make law by saying things. It is natural to think, therefore, that the content of the law is determined by what lawmakers communicate. However, it is sometimes vague what content they communicate, and even when it is clear, the content itself is sometimes vague. In this monograph, Hrafn Asgeirsson examines the nature and consequences of these two linguistic sources of indeterminacy in the law. The aim is to give plausible answers to three related questions: In virtue of what is the law vague? What might be good about vague law? How should courts resolve cases of vagueness? Asgeirsson argues that vagueness in the law is sometimes a good thing, although its value should not be overestimated. He also proposes a strategy for resolving borderline cases, arguing that textualism and intentionalism - two leading theories of legal interpretation - in a significant sense often complement rather than compete with each other"--