Drawing the war, explaining peace: the anatomy of a masterpiece, Guernica, the journey of a painting that has changed the history of art, the paths of an artist and a philosopher and their commitment for peace. Peace is the highest form of understanding, reminds us the philosopher Carlo Sini in his contribution. Peace is not a nostalgia for an unattainable age, but a daily occasion, an exercise of doing, a method. It is not something beyond, but it is a practice and a journey that proceeds in the midst of violence and catastrophes. Peace is the understanding of tragedy, a driving force: we must be able to look for peace facing a tragedy, because those who can not be at peace, have no peace to give.