As promised, this post is on seeing the best in people–judging them charitably, or favorably, rather than indifferently or strictly.
St. Thomas Aquinas explains in an article on favorable judgment, "whether doubtful matters should always be interpreted in the more favorable way", that when a person's fault is not manifest, we should always tend more to judge him in a positive light, to interpret his action in the most favorable light, rather than in the way that is most likely to be true.
But how can that be? St. Teresa Benedicta of the Cross says, "Do not accept anything as the truth if it lacks love, and do not accept anything as love which lacks truth! One without the other becomes a destructive lie." If charity seeks the truth, how can a incorrect judgment really be the charitable judgment?
St. Thomas gives a twofold explanation. On the one hand, it pertains directly to charity to think well of another person when possible, and is contrary to charity to think badly of another possible when not necessary. And on the other hand, it is not a serious problem to be mistaken about a truth such as whether or not someone did something bad. It is a serious matter to be mistaken about universal truths about ourselves and the world (e.g., to be mistaken about whether man has a soul, whether he can be responsible for his actions, etc.), but a mistake about some particular thing is only incidentally bad, and thus when the matter is not clear, but is doubtful, then the consideration of charity or love prevails.