The two series of correspondence between Simone de Beauvoir with both Élisabeth Lacoin (Zaza) and Maurice Merleau-Ponty – published in the volume Lettres d’amitié (Gallimard, 2022) – represent an essential contribution for several reasons. First, these letters offer the possibility of considering the friendship between Beauvoir and Lacoin; then, they also allow us to understand the essential role of Zaza in the development of Simone de Beauvoir’s philosophical and literary project. Finally, these letters also let us know Beauvoir’s attitude during a particular moment in her life that is to say the period when, while she was taking philosophy courses at the Sorbonne, she began to feel the need to write literature, which she discusses with Merleau-Ponty.