The Role of Reasonableness in Self-Defence

20 Pages Posted: 11 Jun 2010 Last revised: 22 Aug 2010

See all articles by Hamish Stewart

Hamish Stewart

University of Toronto - Faculty of Law

Multiple version iconThere are 2 versions of this paper

Date Written: 2003


In this paper, I consider John Gardner's and George Fletcher's arguments that reasonably mistaken defensive force is not justified but excused. I suggest that, when seen through the lens of cases involving the defence of third parties, these arguments can be shown to lead to counter-intuitive results. I suggest further that the source of these results is Gardner's and Fletcher's efforts to characterize reasonably mistaken self-defence by arguing from certain ideas about the conceptual nature of justification, indeed in a fairly abstract way, rather than by arguing from a normative or moral view about the purpose of self-defence. For Gardner, the argument that reasonably mistaken self-defence is merely excused flows directly from the structure of the concept of justification, while for Fletcher, the argument derives from his view that claims of justification can be generalized in a way that excuses cannot. Neither of these arguments depends on establishing the normative underpinnings of self-defence itself; both depend rather on claims about the concept or nature of justification in general. I argue instead that the role of reasonableness in self-defence depends on the normative claim that is being made on behalf of the legal defence; so that the question of whether reasonably mistaken self-defence is an excuse or a justification depends on how the normative theory of self-defence connects with the concept of a justification, and does not depend on the nature of that concept simpliciter. The results generated by Gardner's and Fletcher's approaches might, of course, be correct despite their counter-intuitive feel if they are supported by a persuasive moral theory. I therefore conclude with some thoughts supporting the claim that any plausible approach to criminal liability should treat reasonably mistaken self-defence as justified rather than excused.

Keywords: Criminal Law, Defences, Self-Defence, Justifications and Excuses, Reasonably Mistaken Defensive Force

Suggested Citation

Stewart, Hamish, The Role of Reasonableness in Self-Defence (2003). Canadian Journal of Law and Jurisprudence, Vol. 16, p. 317, 2003, Available at SSRN:

Hamish Stewart (Contact Author)

University of Toronto - Faculty of Law ( email )

78 and 84 Queen's Park
Toronto, Ontario M5S 2C5

Do you have a job opening that you would like to promote on SSRN?

Paper statistics

Abstract Views
PlumX Metrics