Read the passage and answer the question that follows.
What is to be the limit of forgiveness? It would probably have been allowed by many of the ancients that an unforgiving temper was not to be commended. They would have said, we are not to exact a penalty for every nice offense; we are to overlook somethings; we are to be blind sometimes. But they would have said at the same time, we must be careful to keep our self-respect, and to be on a level with the world. On the whole, they would have said, it is the part of a man fully to requite to his friends their benefits and to his enemies their injuries.
Which one of the following is the correct statement? We must ______.