The resort to pretence in both the process of common law reasoning and the language used by other institutions, generally referred to as legal fiction and institutional fiction, respectively (or simply fiction), is a paradoxical phenomenon. On the one hand, it seems to be incompatible with systems that claim to derive their moral legitimacy from the uncompromising quest for hard evidence, fact and truth. On the other, it has a long tradition going back as far as the time of Roman law.¹ It is very common in, and arguably central to, the modern social institutions. It is frequently manifest even to the lay observer.

Even more perplexing is the fact that this phenomenon has rarely invoked the intellectual interest it begs. Indeed, historical accounts of the common law often discuss it and it does have an entry in most legal dictionaries. Yet, the discourse that both these sources display typically tends to avoid problematisation. Moreover, whereas critical articles and scattered comments on specific instances are fairly common, systematic accounts are scarce. Notable among the latter is a pioneering moral critique by Bentham, a neo-Kantian theory by Vaihinger, a programmatic attempt by Fuller and a relatively recent treatise by Eben Moglen.^2–5 In contrast, critiques of ideology qua false consciousness are, of course, abundant; however, these rarely focus on fictions as such. A recent book, though, regards them as part of a broader culture of deception.⁶

In biomedical ethics, however, this paradox has been even more striking. Although legal and institutional fictions have become pivotal to this domain, as this paper will argue, they have virtually been ignored as such. The author has found only one instance where …