Ritual legal fictions

Why do religious legal traditions build devices that satisfy a commandment's letter while plainly sidestepping its point, and why do the devout accept them?

A wire strung round a neighbourhood turns a public street into a private domain, so that carrying a house key on the Sabbath becomes permitted. A loan at interest is written up as a joint venture with a guaranteed profit share, so the prohibition on interest is not engaged. Leavened food is sold to a non-Jew before Passover and bought back afterwards, without leaving the cupboard.

The obvious reading is that these are dodges, tolerated by people who want the law's prestige without its inconvenience. But the devices are laborious, expensive, and require a court's authorisation — and the people using them could simply not observe the rule at all, at no cost. Something is being purchased here, and evasion does not explain what.

Start with what such a rule actually is: a conditional attached to a formal trigger. If these facts obtain, this consequence follows. Carrying is forbidden between domains, so the prohibition depends on how domains are classified. Interest is forbidden on a loan, so it depends on the transaction being a loan.

Now ask what follows. If the rule is a conditional over facts, then changing the facts so the antecedent does not obtain is not a breach of it. It is the rule working exactly as written: nobody carried between domains, because after the boundary there was one domain. That is not sophistry but what a conditional means, and everyone does the same with tax years and deadline gifts.

But that only shows the devices are consistent. It does not explain why anyone would want them, so ask what the alternative would be. The alternative is to say: the point of this rule is not served here, so I will set it aside. The authority of a received law rests on its being given rather than chosen, and the moment you may disapply it wherever you judge its purpose unserved, you have made yourself its legislator. The rule then binds you only when you already agree with it, which is to say not at all. A device keeps the judgement out of your hands.

Look at what the device requires and this becomes concrete. To use a Sabbath boundary you must accept that the Sabbath law applies to you, submit the question to a rabbinic authority, accept its classification, and maintain and inspect the boundary weekly — if the wire breaks, carrying is forbidden again. Every one of those steps is an act of submission to the very law being worked around. The device does not deny the rule's jurisdiction; it is expensive precisely because it affirms it.

The clearest case makes the purpose visible rather than leaving it to inference. Scripture cancels outstanding debts in the seventh year. The Mishnah records the consequence: lenders stopped lending as the seventh year approached, so the poor — the intended beneficiaries — lost access to credit. Hillel instituted the prozbul, by which a lender transfers debts to the court, since the cancellation is written of debts owed to a person. The text is untouched, and the device restores the outcome the text was aimed at. It is a fiction in form and a repair in substance.

Not every device is that clean, and the traditions know it. Jewish jurists distinguish permitted devices from illegitimate contrivance (ha'aramah, recalled), and in Islamic law the status of hiyal has been argued for centuries — Hanafi jurists were comparatively willing to license them, while Ibn Taymiyya and the Hanbali line attacked them as fraud against God (recalled). The interest-avoiding contract is where that dispute bites, because it does not restore the prohibition's purpose as the prozbul does; it arguably dissolves it. Treating all these devices as one approved category flattens a live internal argument.

One system-level effect is worth naming. A fiction concentrates change in an authorised court while leaving the canonical text fixed, so a tradition that cannot amend its scripture can still adapt — licensed, recorded, reversible.

Three refinements, the first correcting a natural misreading.

The account here is functional and external. Practitioners do not generally experience these as fictions. Within the system, the halakhic categories are real: after the boundary is erected the domain genuinely is private, in the only sense of "private" the law employs. Describing that as everyone knowingly pretending gets the internal view wrong, and the wrongness matters — much of the argument between jurists is over whether a classification is correct, which is not a question a pretence could have.

Second, this is not the question whether to break a rule in the case where breaking it would do more good. There the rule is set aside; here it is not touched. The comparison worth holding is with working to rule, where literal compliance is used to withdraw discretion and grind an operation down. A legal fiction is literal compliance run the other way, to create room.

Third, the sceptical reading is not simply wrong, and the traditions supply the argument for it. Where a device leaves a prohibition with no remaining effect, the internal criticism is that the law has been kept in name only. Whether a given instrument does that is decided case by case, by people who disagree, and no general theory settles it.

• Whether the same structure explains secular legal fictions, such as a company being treated as a person.

Every term the collection defines is gathered in the glossary.