Dr Hrafn Asgeirsson

Reader in Philosophy and Law
Ph.D. (University of Southern California)

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

My publications


H Asgeirsson (2020). The Nature and Value of Vagueness in the Law (Hart Publishing)
View abstract View full publication
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, what they communicate is sometimes vague and, even when it is clear, the content itself is sometimes vague. This monograph 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? It argues that vagueness in the law is sometimes a good thing, although its value should not be overestimated. It also proposes a strategy for resolving borderline cases, arguing that textualism and intentionalism – two leading theories of legal interpretation – often complement rather than compete with each other.
H Asgeirsson (2019). "The Sorites Paradox in Practical Philosophy," in S. Oms & E. Zardini (eds.), The Sorites Paradox (Cambridge University Press).
View abstract View full publication
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.