How did Miguel de Unamuno explore Spanish identity and spiritual doubt in his writings?

Miguel de Unamuno, a central figure of the Generation of 1898, explored Spanish identity and spiritual doubt by positioning himself as a provocative thinker who sought to sow "spiritual disquiet".12

Spanish Identity

Unamuno critically examined the "essence" of Spanish national identity in his essay collection En torno al casticismo (1895), where he analyzed Spain’s isolated and anachronistic position in Western Europe. He further explored the Spanish character by re-examining the literary figures of Miguel de Cervantes in Vida de Don Quijote y Sancho (1905), using them as a lens to diagnose the nation's perceived lack of will, or abulia.12

Spiritual Doubt

Unamuno’s work is defined by the tension between intellect and emotion, and faith and reason. In his seminal work, The Tragic Sense of Life in Men and Peoples, he articulated the agony caused by the conflict between a human's rational denial of immortality and their passionate, innate longing for it. He utilized the novel as a medium to depict agonized characters who voiced these philosophical struggles, culminating in his exploration of Kierkegaardian existentialism in works like San Manuel Bueno, mártir.12