The onus of proving a fact rests upon the man.
Explanation & Origin
The sixth-century Digest of Justinian (22.3.2) provides, as a general rule of evidence: Ei incumbit probatio qui dicit, non qui negat means “Proof lies on him who asserts, not on him who denies”. It is there attributed to the second and third century jurist Paul. It was introduced in Roman criminal law by emperor Antoninus Pius.
The presumption of innocence is the legal principle that one is considered innocent unless proven guilty. It was traditionally expressed by the Latin maxim ei incumbit probatio qui dicit, non qui negat (“the burden of proof is on the one who declares, not on one who denies”).
The trier of fact (a judge or a jury) is thus restrained and ordered by law to consider only actual evidence and testimony presented in court. The prosecution must, in most cases prove that the accused is guilty beyond reasonable doubt. If reasonable doubt remains, the accused must be acquitted.
Many civil law systems including Brazil, Italy, Philippines, Poland and Spain have adapted this principle.
A , was accused of robbing a store clerk at knife point. A , was arrested, charged, and brought to trial. The prosecution must prove all elements of the crime of robbery. The prosecution produces the testimony of the store clerk and a shopper who witnessed the attack. Both the store clerk and shopper identify A as the attacker. They both also say that a knife was used in the attack. The prosecution also produces a knife that they found in A’s pocket when they arrested A. In a police interview (a recording of which was played for the jury), A , admit to owning the knife.
Lalubhai Surchand vs Bai Amrit And Others [I. L. R., 2 Bom.]
In this case the principle of “ei incumbit probatioqui dicit, non ei qui negat” laid down as determining the burden of proof equally in equity proceedings as in trials at Common Law, and as an illustration it is said: “If, for instance, an answer states a purchase for a valuable consideration without notice, and they go into evidence, the plaintiff will have to prove the notice.”
Mr. Mahesh Bora vs Unknown [12th May 2015]
This case analyzed the concept of burden of proof in a criminal trial. Burden of proof is based on the rule ei incumbit probatio qui dicit, non qui negat, i.e. burden of proving a fact rests  on the party who substantially asserts the affirmative of the issue and not upon the party who denies it; for a negative is usually incapable of proof.
Dr. Om Prakash Rawal vs Mr. Justice Amrit Lal Bahri [AIR 1992 SC 1526]
The rule of evidence enshrined in Section 101 of the Evidence Act is based on the well known maxim ei incumbit probatio, qui dicit, non qui negate, which means the burden of proof is on the party who asserts, not on him who denies.
M/S G.D. Engineering Works vs Arvind Kumar [W.P.(C) No. 474 of 2014]
It has been repeatedly held that so far as an industrial claim is concerned, its procedure is guided by the general principles of the law of evidence that he who asserts must prove. Based on the rule of Roman Law – `ei incumbit probatio, qui dicit, non qui negat‘ – the burden of proving a fact rests on the party who substantially asserts the affirmative of the issue and not upon the party who denies it, for a negative does not admit of direct and simple proof.
Edited by Vigneshwar Ramasubramania
Approved & Published – Sakshi Raje