Miguel de Unamuno (1864–1936) was a famous Spanish writer, philosopher and poet. This publication includes two large philosophical essays by Unamuno, translated into Russian for the first time. They most fully present Unamuno's philosophical credo, the main ideological problems of his work, as well as the existential style of philosophizing, one of the founders of which was the Spanish thinker. Both books were a significant event in the intellectual life of Spain and Europe at the beginning of the century. The book is intended for a wide range of readers. It will be of interest to everyone who is concerned about the eternal question of the meaning of human existence.