The rule of friendship means there should be mutual sympathy between them, each supplying what the other lacks and trying to benefit the other, always using friendly and sincere words.
We can more easily avenge an injury than requite a kindness; on this account, because there is less difficulty in getting the better of the wicked than in making one's self equal with the good.
It is not easy to distinguish between true and false affection, unless there occur one of those crises in which, as gold is tried by fire, so a faithful friendship may be tested by danger.