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Alexy on Necessity in Law and Morals


  • For comments on drafts of this article, my thanks to Brian Bix, Charles Collier, Ken Ehrenberg, Kim Ferzan, Rashad Ibanov, Hans Oberdiek, John Oberdiek, Ralf Poscher, Veronica Rodriguez-Blanco, Guilherme Vasconcelos Vilaca, and Jefferson White. I thank my research assistant, Anna Södersten, for her assistance with this article.


Robert Alexy has built his original theory of law upon pervasive claims for “necessary” features of law. In this article, I show that Alexy's claims suffer from two difficulties. First, Alexy is never clear about what he means by “necessity.” Second, Alexy writes as if there have been no challenges to claims of conceptual necessity. There have been such challenges and Alexy needs to answer them if his project is to succeed.