it is a great point in every good system of laws to determine exactly the credibility of witnesses and the proofs of guilt every reasonable man—that is, every man with a certain connection between his ideas and with feelings like those of other men—is capable of bearing witness. the true measure of his credibility is only the interest he has in speaking or in not speaking the truth; so that nothing can be more frivolous than to reject the evidence of women on the pretext of their feebleness, nothing more childish than to apply the results of real death to civil death as regards the testimony of the condemned, nothing more unmeaning than to insist on the mark of infamy in the infamous when they have no interest in lying.

among other abuses of grammar, which have no slight influence on human affairs, that one is notable which makes the evidence of a condemned criminal null and void. ‘he is dead civilly’ say gravely the peripatetic lawyers, ‘and a dead man is incapable of any action.’ in support of this silly metaphor many[139] victims have been sacrificed, and it has very often been disputed with all seriousness whether the truth should not yield to judicial formulas. provided that the testimony of a condemned criminal does not go to the extent of stopping the course of justice, why should not a fitting period be allowed, even after condemnation, both to the extreme wretchedness of the criminal and to the interests of truth, so that, by his adducing fresh matter to alter the complexion of the fact, he may justify himself or others in a new trial? forms and ceremonies are necessary in the administration of justice, because they leave nothing to the free will of the administrator; because they give the people an idea of a justice which is not tumultuary and self-interested, but steadfast and regular; and because men, the slaves of habit and imitation, are more influenced by their feelings than by arguments. but such forms can never without fatal danger be so firmly fixed by the laws as to be injurious to truth, which from being either too simple or two complex needs some external pomp to conciliate the ignorant populace.

the credibility, therefore, of a witness must diminish in proportion to the hatred, friendship, or close connection between himself and the accused. more than one witness is necessary, because, so long as one affirms and another denies, nothing is proved, and the right which everyone has of being held innocent prevails.[140] the credibility of a witness becomes appreciably less, the greater the atrocity of the crime imputed,[66] or the improbability of the circumstances, as in charges of magic and gratuitously cruel actions. it is more likely, as regards the former accusation, that many men should lie than that such an accusation should be true, because it is easier for many men to be united in an ignorant mistake or in persecuting hatred than for one man to exercise a power which god either has not conferred or has taken away from every created being. the same reasoning holds good also of the second accusation, for man is only cruel in proportion to his interest to be so, to his hatred or[141] to his fear. properly speaking, there is no superfluous feeling in human nature, every feeling being always in strict accordance with the impressions made upon the senses. in the same way the credibility of a witness may sometimes be lessened by the fact of his being a member of some secret society, whose purposes and principles are either not well understood or differ from those of general acceptance; for such a man has not only his own passions but those of others besides.

lastly, a witness’s evidence is almost null when spoken words are construed into a crime. for the tone, the gesture, all that precedes or follows the different ideas attached by men to the same words, so alter and modify a man’s utterances, that it is almost impossible to repeat them exactly as they were spoken. moreover, actions of a violent and unusual character, such as real crimes are, leave their traces in the numberless circumstances and effects that flow from them; and of such actions the greater the number of the circumstances adduced in proof, the more numerous are the chances for the accused to clear himself. but words only remain in the memory of their hearers, and memory is for the most part unfaithful and often deceitful. it is on that account ever so much more easy to fix a calumny upon a man’s words than upon his actions.