Thomas Aquinas

“ One may interpret something for the worst or for the best in two ways. First, by a kind of supposition; and thus, when we have to apply a remedy to some evil, whether our own or another's, in order for the remedy to be applied with greater certainty of a cure, it is expedient to take the worst for granted, since if a remedy be efficacious against a worse evil, much more is it efficacious against a lesser evil. ”

“ The second degree is when a man, from slight indications, esteems another man's wickedness as certain. This is a mortal sin, if it be about a grave matter, since it cannot be without contempt of one's neighbor. Hence the same gloss goes on to say: "If then we cannot avoid suspicions, because we are human, we must nevertheless restrain our judgment, and refrain from forming a definite and fixed opinion." The third degree is when a judge goes so far as to condemn a man on suspicion: this pertains directly to injustice, and consequently is a mortal sin. ”

“ The habits of knowledge and justice are perfections of the individual, and consequently their absence does not make a judgment to be usurped, as in the absence of public authority which gives a judgment its coercive force. ”

“ Now since it belongs to the same authority to interpret and to make a law, just as a law cannot be made save by public authority, so neither can a judgment be pronounced except by public authority, which extends over those who are subject to the community. Wherefore even as it would be unjust for one man to force another to observe a law that was not approved by public authority, so too it is unjust, if a man compels another to submit to a judgment that is pronounced by other than the public authority. ”

“ Since then human judgment is about human acts, which are about singular and contingent matters, it seems that no judgment would be lawful, if it were not lawful to judge from suspicions.
Objection 2: Further, a man does his neighbor an injury by judging him unlawfully. But an evil suspicion consists in nothing more than a man's opinion, and consequently does not seem to pertain to the injury of another man. Therefore judgment based on suspicion is not unlawful. ”

“ Now no man ought to despise or in any way injure another man without urgent cause: and, consequently, unless we have evident indications of a person's wickedness, we ought to deem him good, by interpreting for the best whatever is doubtful about him.
Reply to Objection 1: He who interprets doubtful matters for the best, may happen to be deceived more often than not; yet it is better to err frequently through thinking well of a wicked man, than to err less frequently through having an evil opinion of a good man, because in the latter case an injury is inflicted, but not in the former. ”

“ The spiritual man, by reason of the habit of charity, has an inclination to judge aright of all things according to the Divine rules; and it is in conformity with these that he pronounces judgment through the gift of wisdom: even as the just man pronounces judgment through the virtue of prudence conformably with the ruling of the law. ”

“ Further, man should love his neighbor as himself. Now with regard to himself, a man should interpret doubtful matters for the worst, according to Job 9:28, "I feared all my works." Therefore it seems that doubtful matters affecting one's neighbor should be interpreted for the worst.
On the contrary, A gloss on Rom. 14:3, "He that eateth not, let him not judge him that eateth," says: "Doubts should be interpreted in the best sense." ”

“ It would seem that it is not unlawful to form a judgment from suspicions. For suspicion is seemingly an uncertain opinion about an evil, wherefore the Philosopher states (Ethic. vi, 3) that suspicion is about both the true and the false. ”

“ Reply to Objection 1: Some kind of certainty is found in human acts, not indeed the certainty of a demonstration, but such as is befitting the matter in point, for instance when a thing is proved by suitable witnesses. ”

“ First, from a man being evil in himself, and from this very fact, as though conscious of his own wickedness, he is prone to think evil of others, according to Eccles. 10:3, "The fool when he walketh in the way, whereas he himself is a fool, esteemeth all men fools." Secondly, this is due to a man being ill-disposed towards another: for when a man hates or despises another, or is angry with or envious of him, he is led by slight indications to think evil of him, because everyone easily believes what he desires. ”

“ Even as unjust laws by their very nature are, either always or for the most part, contrary to the natural right, so too laws that are rightly established, fail in some cases, when if they were observed they would be contrary to the natural right. ”

“ Secondly we may interpret something for the best or for the worst, by deciding or determining, and in this case when judging of things we should try to interpret each thing according as it is, and when judging of persons, to interpret things for the best as stated above. ”