Giving the devil his due is a phrase that means to acknowledge someone's bad qualities despite their good qualities. There are several synonyms for this phrase, including "credit where credit is due", "seeing both sides", "grudging respect", and "acknowledging the negative". These phrases all convey the same idea of recognizing someone's faults while still giving them their due. It is important to acknowledge both the good and bad qualities of a person or situation to have a balanced and fair understanding. So, whether you use the phrase "giving the devil his due" or one of its synonyms, remember to acknowledge both the positives and negatives.