Hermann Hesse's correspondence with Stefan Zweig was extended for a period of thirty-five years-despite the reservations of the first to deal with writers- until the latter's death in 1942. Through these letters, the reader will attend the construction of a common thought between these two great authors, committed to the unequivocal defense of reason, goodness and humanity in turbulent times, confirming that no aesthetic that can exist without the framework of ethical thinking that support it.