Summa Theologiae II-II, 60:4
Whether doubtful matters should always be interpreted in the more favorable way
It seems that doubtful matters should not always be interpreted in the more favorable way.
1. For judgment seems to be more about that which happens for the most part. But for the most part it happens that people act badly, since “the number of fools is infinite,” as is said in Ecclesiastes 1:15 (Vulgate); for “the imagination of man’s heart is evil from his youth,” as is said in Gen 8:21. Therefore we should interpret doubtful things rather on the side of the bad than on the side of the good.
2. Further, Augustine says that he lives piously and righteously who is an honest judger of things, turning to neither side. But he who interprets favorably that which is doubtful, turns to one side. Therefore one should not do this.Continue reading Aquinas on Charitable or Favorable Judgment