- 1 : presumptuous attitude or conduct : audacity
- 2a : an attitude or belief dictated by probability : assumption
- 3: a legal inference as to the existence or truth of a fact not certainly known that is drawn from the known or proved existence of some other fact
In the law of evidence, a presumption of a particular fact can be made without the aid of proof in some situations. The types of presumption includes a rebuttable discretionary presumption, a rebuttable mandatory presumption, and an irrebutable or conclusive presumption. The invocation of a presumption shifts the burden of proof from one party to the opposing party in a court trial. Presumptions are sometimes categorized into two types: presumptions without basic facts, and presumptions with basic facts. In the United States, mandatory presumptions are impermissible in criminal cases, but permissible presumptions are allowed.
The ancient Jewish law code, the Talmud, included reasoning from presumptions (hazakah), propositions taken to be true unless there was reason to believe otherwise, such as "One does not ordinarily pay a debt before term." The same concept was found in ancient Roman law, where, for example, if there was doubt as to whether a child was really the issue of someone who had left money in a will, the presumption was in favor of the child. Medieval Roman and canon law graded presumptions according to strength: light, medium or probable, and violent. These gradings and many individual presumptions were taken over into English law in the seventeenth century by Edward Coke.
- types: Rebuttable presumption, Conclusive presumption
- examples of presumption without basic facts: Presumption of innocence
- example of presumption with basic facts: Death in absentia, e.g. law says if a person has been missing for 7 years or more (basic fact), that person shall be presumed to be dead.
- J. Franklin, The Science of Conjecture: Evidence and Probability Before Pascal (Baltimore: Johns Hopkins University Press, 2001), 6.