Re-evaluation suggests and presupposes a prior evaluation. If evidence has already been evaluated by the trial Court, on what grounds, on what basis, on what principles would an appellate court undertake another re-evaluation of the same evidence? Before tackling this main issue, it may be necessary to dispose of a subsidiary but related issue: What does evaluation of evidence consist of? What is the meaning of the expression evaluation? To evaluate simply means to give value to, to ascertain the amount, to find numerical expression for etc. Thus if a plaintiffs case is supported by witnesses, while the defendant’s case is supported by 6 witnesses then the numerical expression, the quantum of evidence, the amount, would be 4 to 6. If cases are decided solely by the number of witnesses called by either side, then in the above instance the plaintiff will lose, having a preponderance of 6 witnesses to 4 witnesses in the scale against him. Now talking of scale naturally leads one to the famous dictum of Fatayi Williams, J.S.C.(as he then was) in A.R. Mogaji and ors v. Madam Rabiatu Odafin and ors (1978) 4 S.C.91 at 93:- “When an appellant complains that a judgment is against the weight of evidence, all he means is that when the evidence adduced by him is balanced against that adduced by the respondent, the judgment given in favour of the respondent is against the weight which have been given to the totality of the evidence before him, (the trial Judge) ….. Therefore in deciding whether certain set of facts given in evidence by one party in a civil case before a court in which both parties appear is preferable to another set of facts given in evidence by the other party, the trial Judge, after a summary of all the facts, must put the two sets of facts on an imaginary scale, weigh one against the other, then decide upon the preponderance of credible evidence which weighs more, accept it in preference to the other, and then apply the appropriate law to it ….” (italics ours). This scale though imaginary is still the scale of justice, and the scale of truth. Such a scale will automatically repel and expel any and all false evidence. What ought to go into that imaginary scale should therefore be no other than credible evidence. What is therefore necessary in deciding what goes into the imaginary scale is the value, credibility and quality as well as the probative essence of the evidence.
— Oputa JSC. Onwuka & Ors. V. Ediala & Anor. (SC.18/1987, 20 January 1989)