San Diego Law Review


Peter Westen

Library of Congress Authority File


Document Type



An assailant is on the verge of shooting a hated rival, Jones, when Jones, oblivious to the attack, decides in that instant to kill his assailant, thereby becoming what commentators call an “unknowing self-defender” or “unwittingly justified actor.” By its terms, Jones is guilty of an impossibility attempt under the Model Penal Code because he satisfies all the elements of attempted murder under the Code. The question, which has divided commentators since George Fletcher and Paul Robinson’s debate in the 1970s, is whether Jones is also guilty of the completed crime of murder and whether the latter is the more appropriate charge. Anthony Duff, for one, has said that the debate seems“irresoluble.” I agree that the debate is irresoluble but only so long as commentators continue to ignore the issue on which the answer must turn, namely, why resulting harms matter in criminal law -- that is, why criminal law distinguishes in name and penalty between impossibility attempts and complete crimes. Commentators differ regarding why resulting harm matters. I examine what I regard as the most promising account, one that originates with Plato. Based on Plato’s account, I argue that most, of not all, acts of unwitting justification should be punished as impossibility attempts rather than as completed crimes.

Included in

Criminal Law Commons