The most difficult province in friendship is the letting a man see his faults and errors; which should, if possible, be so contrived that he may perceive our advice is given him not so much to please ourselves as for his own advantage. The reproaches, therefore, of a friend should always be strictly just, and not too frequent.
Does a man reproach thee for being proud or ill-natured, envious or conceited, ignorant or detracting? Consider with thyself whether his reproaches are true. If they are not, consider that thou art not the person whom he reproaches, but that he reviles an imaginary being, and perhaps loves what thou really art, though he hates what thou appearest to be. If his reproaches are true, if thou art the envious, ill-natured man he takes thee for, give thyself another turn, become mild, affable, and obliging, and his reproaches of thee naturally cease. His reproaches may indeed continue, but thou art no longer the person whom he reproaches.