affirmanti non neganti incumbit probatio
Meaning. The burden of proof lies on the one who affirms, not on the one who denies.
A person who asserts a fact must prove it; the person who merely denies it need not prove the negative. The maxim is the basis of the BSA rule that whoever wants the court to give judgment on a legal right depending on facts must prove those facts, and that the burden lies on the person who would fail if no evidence were given on either side.
It is a general rule, not absolute. A statute may shift the burden (for example, presumptions in dowry death or the facts especially within a person's knowledge), and in some cases a negative must be proved, though less evidence is needed for it.
Example
The plaintiff who said the loan was given had to prove it, since affirmanti non neganti incumbit probatio; the defendant's bare denial needed no proof.
In Indian law
- Section 104, Bharatiya Sakshya Adhiniyam, 2023 (old s.101 Evidence Act): burden of proof
- Section 105, Bharatiya Sakshya Adhiniyam, 2023 (old s.102 Evidence Act): on whom burden lies