Miguel de Unamuno y Jugo (1864-1936) was an essayist, novelist, poet, playwright and philosopher from Spain. He served as rector of the University of Salamanca for two periods: from 1900 to 1924 and 1930 to 1936, during a time of great social and political upheaval. His philosophy was not systematic, but rather a negation of all systems and an affirmation of faith "in itself. " He developed intellectually under the influence of rationalism and positivism, but during his youth he wrote articles that clearly show his sympathy for socialism and his great concern for the situation in which he found Spain at the time. The title of Unamuno's most famous work, Del Sentimiento Tragico de la Vida (Tragic Sense of Life), refers to the human condition of the desire above all else for immortality when faced with the certainty of death.