Mere

“It is a considerable point in all good legislation to determine exactly the credibility of witnesses and the proofs of a crime. Every reasonable man, everyone, that is, whose ideas have a certain interconnection and whose feelings accord with those of other men, may be a witness. The true measure of his credibility is nothing other than his interest in telling or not telling the truth; for this reason it is frivolous to insist that women are too weak [to be good witnesses], childish to insist that civil death in a condemned man has the same effects as a real death, and meaningless to insist on the infamy of the infamous, when they have no interest in lying.”
― Cesare Beccaria, On Crimes and Punishments and Other Writings