negative evidence

Testimony that a fact did not exist or that a thing was not done, in other words testimony that denies rather than affirms. 30 Am J2d Ev § 1092. Testimony that one did not see or hear something, otherwise called testimony to negative knowledge. Union P. R. Co. v Burnham (CA10 Colo) 124 F2d 500. "The trial judge practically told the jury that negative testimony was confined to that of a witness who, though present at a transaction, says that he did not see or hear." This is too limited a rule. Testimony which is positive in form may amount merely to negative testimony. Smith v Milwaukee Builders & Traders' Exchange, 91 Wis 360, 64 NW 1041. The probative force of negative testimony depends largely upon circumstances. In some circumstances, its probative force may be so slight as to reach the vanishing point; in others, it may be more persuasive than the positive testimony of some witnesses. It is only when it is so clear that such testimony has no probative value whatever that reasonable men would not differ in their conclusions in reference thereto that courts are justified in disregarding it on the ground that it does not rise to the dignity of evidence. Union Pacific R. Co. v Burnham (CA 10 Colo) 124 F2d 500.