Remember, that the end of true friendship is the good of its object, and the cultivation of virtue, in two hearts emulous of each other, and desirous to perpetuate their society beyond the grave. Nothing can be more contrary to this end than that mutual intercourse of flattery, which some call friendship. A real friend will venture to displease me, rather than indulge my faulty inclinations, or increase my natural frailties; she will endeavour to make me acquainted with myself, and will put me upon guarding the weak parts of my character. Friendship, in the highest sense of the word, can only subsist between persons of strict integrity and true generosity. Before you fancy yourself possessed of such a treasure, you should examine the value of your own heart, and see how well it is qualified for so sacred a connection; and then a harder task remains--to find out whether the object of your affection is also endued with the same virtuous disposition. Youth and inexperience are ill able to penetrate into characters: the least appearance of good attracts their admiration, and they immediately suppose they have found the object they pursued. It is a melancholy consideration, that the judgement can only be formed by experience, which generally comes too late for our own use, and is seldom accepted for that of others. I fear it is in vain for me to tell you what dangerous mistakes I made in the early choice of friends--how incapable I then was of finding out such as were fit for me, and how little I was acquainted with the true nature of friendship, when I thought myself most fervently engaged in it! I am sensible all this will hardly persuade you to choose by the eyes of others, or even to suspect that your own may be deceived. Yet, if you should give any weight to my observations, it may not be quite useless to mention to you some of the essential requisites in a friend; and to exhort you never to choose one in whom they are wanting.