Legal fiction

A legal fiction is a fact assumed or created by courts which is then used in order to apply a legal rule. Typically, a legal fiction allows the court to ignore a fact that would prevent it from exercising its jurisdiction, by simply assuming that the fact is different. This is the case with the Bill of Middlesex where the Court of King's Bench could only exercise jurisdiction over cases which took place in the historic English county of Middlesex. To allow the Court, which was the central court of the land, to take jurisdiction over other cases, parties began to plead that, along with the other facts, there had also been a trespass which occurred in Middlesex. This allowed the King's Bench to rule on the whole of the case.

Legal fictions are different from legal presumptions which assume a certain state of facts until the opposite is proved, such as the presumption of legitimacy. They are different from hypothetical examples, such as the 'reasonable person' which serve as tools for the court to express its reasoning. They are also different from legal principles which create a legal state of affairs that is different from the underlying facts, such as corporate personality although these are sometimes wrongly called legal fictions.

The term "legal fiction" is not usually used in a pejorative way, and has been likened to scaffolding around a building under construction.

One example of a legal fiction occurs in adoption. Once an order or judgment of adoption (or similar decree from a court) is entered, one or both biological (or natural) parents becomes a legal stranger to the child, legally no longer related to the child and with no rights related to him or her. Conversely, the adoptive parent(s) are legally considered to be the parent(s) of the adopted child; a new birth certificate reflecting this is issued. The new birth certificate is a legal fiction.

The concept of the law treating corporate entities as if they were persons dates back to Ancient Rome.

This simple fiction enabled corporations to acquire wealth, expand, and become the preferred organizational form for businesses of all sizes. Corporate personhood has come under criticism recently, as courts have extended other rights to the corporation beyond those necessary to ensure their liability for debts. Other commentators argue that corporate personhood is not a fiction anymore; it simply means that for some legal purposes, "person" has now a wider meaning than it had before and it still has in non-legal uses. In jurisdictions using this fiction, a legal drafter may distinguish between a "person" and a "natural person" to specify the scope of legislation.

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