The Spanish poet Juan Ramón Jiménez (1881–1958; Nobel laureate 1956) wrote at a key moment in literary history. Since Jiménez’s lyrical output covers the poetic tradition from Romanticism through Symbolism to the Avant-Gardes, his work can be regarded as a condensation of the modern paradigm. Julio Jensen investigates the lyrical subject appearing in Jiménez’s poetry as exemplary of the notion of modern subjectivity. He does so by assuming a historical correlation between literature and philosophy in the sense that if philosophical discourse conceptualizes the prevailing understanding of the human being at a given moment, literary discourse represents it. Modern thought does not accept any other foundation than subjectivity. At the same time, the awareness of the subject’s finitude engenders pessimism with respect to its status as world-generating principle. One of the primary aims of this study, then, is to show how Jiménez poignantly enacts this vacillation between self-enthronement and self-eradication. With insightful readings of Jiménez’s poetry, the author opens a rich vein in the work of a writer who would serve as a central reference for later Spanish-language poets such as Federico Garcá Lorca, Pablo Neruda and Octavio Paz.