ORIGINAL PAPER Excusing Necessity and Terror: What Criminal Law Can Teach Constitutional Law Alan Brudner Published online: 25 November 2008 Ó Springer Science+Business Media B.V. 2008 Abstract This essay proposes a theory of excuse that, without blending it into excul- pation, avoids the condonation of crime. The question it takes up is: given that neither compulsion by circumstances nor by human threats removes the legal reason for punishing, how can its exonerating force be rendered compatible with the state’s general duty to punish the guilty? The chapter criticizes various proposals for reconciling excuse with the duty to punish the guilty, including the moral involuntariness theory, the concession to frailty theory, and the conformity to moral expectation theory. It then proposes a solution: moral blamelessness exonerates because it simulates the conditions for legal exculpation. Just as the exculpated actor acknowledges the legal norm of mutual respect for agents, so does the excused actor acknowledge the public reason of the self-sufficient political community of which the legal norm is a part. The author argues that this theory would excuse the altruistic no less than the self-preferring murderer. Keywords Excusing necessity Á Criminal law Á Terrorism The German Constitutional Court and the Luftsicherheitsgesetz In June, 2004, the German Bundestag enacted the Luftsicherheitsgesetz (Air Security Act) in order to prevent terrorist attacks of the kind suffered in New York and Washington on September 11, 2001. Section 14 (3) of the Act empowered the Minister of Defence to order the Air Force to shoot down a hijacked commercial airplane full of passengers if he concluded that the plane would be used to kill human beings and if no less drastic means would prevent an imminent catastrophe. This is a revised version of a paper presented at the International Symposium on Criminal Law in Times of Emergency, Hebrew University of Jerusalem, May 21–22, 2008. A. Brudner (&) Faculty of Law, University of Toronto, Toronto, Canada e-mail: alan.brudner@utoronto.ca 123 Crim Law and Philos (2009) 3:147–166 DOI 10.1007/s11572-008-9068-z