There are three friendships which are advantageous, and three which are injurious. Friendship with the upright; friendship with the sincere; and friendship with the man of much observation: these are advantageous. Friendship with the man of specious airs; friendship with the insinuatingly soft; and friendship with the glib-tongued: these are injurious.
First and foremost, be faithful to your superiors, keep all promises, refuse the friendship of all who are not like you; and if you have made a mistake, do not be afraid of admitting the fact and amending your ways.
We need to strengthen such inner values as contentment, patience and tolerance, as well as compassion for others. Keeping in mind that it is expressions of affection rather than money and power that attract real friends, compassion is the key to ensuring our own well-being.
We poets would die of loneliness but for women, and we choose our men friends that we may have somebody to talk about women with. Letter to Olivia Shakespeare, 1936