Introduction. Miguel de Unamuno is a Spanish philosopher who pondered over the question of the meaning of human existence and the purpose of life. The anxiety about death generates in individuals a desire for immortality, which finds its expression in what M. de Unamuno termed as the “tragic feeling of life”. Theoretical analysis. The proposed examination focuses on the concept of aspiration as articulated by M. de Unamuno, employing both dialectical and hermeneutic methodologies. This desire is reinforced by the dialectical conception of humanity, in which people debate between the rational and the irrational (passionate, vital, spiritual, volitional). Both categories define human existence and create an internal conflict: people pretend that reason (rationality) guides their path, but they are often led by passion and feelings (irrationality). The research involves an analysis of the concept of «desire» as articulated by M. de Unamuno, which is a relatively underexplored issue in domestic philosophy. Conclusion. Conclusions are formulated regarding what the Spanish philosopher understands by "the desire for immortality".