chapter  11
Alon Harel and Assaf Sharon (2011), '"Necessity Knows No Law": On Extreme Cases and Uncodifiable Necessities
Pages 22

Doubtlessly, articulating rough-and-ready identity conditions for extreme cases is difficult, maybe even impossible. Nevertheless, although the need to determine whether a certain situation counts as extreme or not may arise (when an actor's decision is contested in court, for example), and acknowledging that hard cases are unavoidable, we venture to speculate that these will be the exception, not the rule. Given the nature of extreme cases - they are, after all, extreme - the common cases will be clear-cut. For, if a situation is not clearly extreme, it will normally not constitute an exception. For the most part, at least, extreme cases fit the label, 'you know it when you see it.'* In any case, we should not let this epistemic difficulty undermine the moral category of extreme cases. Clearly, no general detailed criteria can be given for what constitutes such cases and vague and borderline cases are undoubtedly possible. But these shortcomings are unavoidable in matters such as these and need not detract from the plausibility of the present account.