The thirteen studies gathered in this volume had as their starting point the International Colloquium Solitude, Soledade, Solitude, Sozinhice: Social Problem or Personal Choice?, organized by CITCEM’s “Literature and Intercultural Dialogues” research group, and held at the Casa dos Livros of the University of Porto, on November 22 and 23, 2023. From the first work of European Literature to Jungian Psychoanalysis, through the Synoptic Gospels and a whole cultural and literary tradition that is not subsumed in the West, being alone has multiple meanings, not always fixed by the phenomenology of the circumstance that mediates the subject. The problematization inherent in the theme has led to the exploration of different perspectives on loneliness, which both converges in the etymological echo of saudade in the archaic soledade, as well as that benign aura of communion with oneself identified in solitude, or even intensifies in the disconcerting neologism authenticated by Luandino Vieira: sozinhice.