Friendship is something so good that no one would want to live a life without friends, the classics said. From this statement has arisen a long philosophical and literary tradition that has praised the value of friendship and continues today through series, cinema, and self-help proposals. The common thread of this tradition is that there is a perfect or true friendship, even pure, which is not confused with the exchanges of social life nor with the dependencies of other bonds. The value of friendship is placed at the center, because if something makes us suffer nowadays, it is our lives doomed to falseness, isolation, and unwanted loneliness. This book starts from a suspicion towards this ethical ideal of friendship. What hides behind this ideal of purity? How has it been able to remain stable over time and to whom is it addressed? Who does it leave out? Does it help us explain the meaning, pain, and fears that cross our friendships? Pulling the thread of these questions reveals another way of understanding the role friends play in our lives. Why are they there? We could live perfectly socialized perfect lives through a partner, family, work, or our hobbies, and never have a single friend. In fact, friendship is the only stable social relationship for which we have not invented any institution. We do not enroll or register, nor do we sign any law or contract to be friends. Friendship is a strange passion that opens the door to the world of strangers.
