Definition
Legem amittere (Latin: "to lose one's law") is a historical legal phrase describing the forfeiture of a person's right to be admitted to take an oath in a court of law. In medieval English legal practice, a person who suffered this consequence was rendered incompetent as a witness or oath-taker — effectively stripped of legal standing to participate in proceedings that depended on sworn testimony. The sanction was typically imposed as a result of conviction for certain crimes, particularly those involving dishonesty or moral turpitude, on the theory that a person of demonstrated bad character could not be trusted to swear truthfully.
Common Confusion
Legem amittere is sometimes loosely grouped with the broader concept of civil death or outlawry, but it is more precise and narrower. Civil death extinguished most civil rights; outlawry placed a person entirely outside legal protection. Legem amittere addressed specifically the loss of oath-competency — the incapacity to give sworn testimony — which was a distinct and significant disability in a legal system that relied heavily on compurgation and sworn proof. The three concepts could coexist or overlap in a given case, but they are not synonymous.
Why It Matters in Research
This term appears almost exclusively in sources dealing with early and medieval English common law, and researchers are unlikely to encounter it in post-eighteenth-century materials except as a historical reference. Several research traps are worth noting.
First, the significance of losing oath-competency is easy to underestimate from a modern vantage point. In medieval legal procedure, the ability to swear an oath was not merely evidentiary — it was foundational. Compurgation, the process by which a party cleared themselves of accusation by swearing with oath-helpers, depended entirely on the credibility and legal standing of those involved. A person who had lost their law could neither purge themselves nor serve as a compurgator for another. This made legem amittere a genuinely devastating procedural sanction.
Second, the phrase sits within a cluster of Latin terms describing degraded legal status, including infamia, attainder, and outlawry. Corpus researchers working in early Year Books, plea rolls, or treatises such as Bracton or Glanvill will encounter these terms in proximity and need to distinguish them carefully. Legem amittere concerns testimonial incapacity specifically; conflating it with attainder (which carried property forfeiture and blood corruption) or infamia (the Roman law concept of reputational disgrace affecting legal standing) will produce analytical errors.
Third, the concept did not survive intact into modern evidence law, but its legacy is visible in the historical rules disqualifying convicted felons and persons with prior convictions from testifying — rules that persisted in English and American law well into the nineteenth century and in some jurisdictions into the twentieth. Researchers tracing the history of witness competency rules will find legem amittere a useful point of origin in that doctrinal lineage.
Historical Dictionary Support
Black's Law Dictionary defines the term concisely: "To lose one's law; that is, to lose one's privilege of being admitted to take an oath." This is accurate as far as it goes, but the entry's brevity leaves the full procedural and historical weight of the concept unexpressed.
Historical legal treatises provide richer context. Bracton's De Legibus et Consuetudinibus Angliae discusses categories of persons who are incompetent to take an oath or to appear as witnesses, including those convicted of infamous crimes, and the underlying rationale — that a dishonest person's oath carries no legal weight — is developed there more fully than any dictionary entry conveys. Glanvill similarly addresses the mechanics of compurgation and the conditions that disqualify participants.
The historical dictionaries are in agreement that this is a term of art with no meaningful modern survival in its original form. What they do not address, and what researchers should supply for themselves, is the connection between this medieval sanction and the later common law rules on witness incompetency that carried some of the same logic forward under different names and doctrinal frameworks.
Jurisdictional Note
Legem amittere is a term of English common law origin and has no direct analogue in civil law systems. American legal materials will reference it, if at all, only in historical or scholarly contexts tracing the roots of evidence doctrine. It is not operative law in any current jurisdiction.