The brief taste of diplomatic life which he had had seems to have put an end to any really creative activity. A tribute to the memory of the young poet Francisco Zea, written in May, 1858,[7] contains what is really his farewell to a life of letters. Therein, after discussing the pessimistic statement of Larra that in Spain "No se lee porque no se escribe, y no se escribe porque no se lee," he declares that people in Spain are writing, but that no one is reading. It is not the fault of those who write, he continues, and waste the treasures of their youth in a fruitless struggle. In Spain one must write for pure love of letters, and unfortunately this is the most platonic of loves. There are few readers of literature in general, and of lyric poetry almost none. He resents the intrusion of the latter into the drama, where it is heard with pleasure by people, comfortably seated in stalls, who in the morning could not endure Fray Luis de León or Francisco de la Torre. His small stock of patience exhausted, Sanz turned to diplomatic life.
On the eleventh of August of 1859 he was appointed Minister to the Empire of Brazil, and on the same day he was named representative in the Cortes. A month later he wrote to the Secretary of State to say that he must resign the post "for reasons which I have had the honor to submit verbally to your Excellency's consideration." At this time he seems to have gone into complete retirement, resisting the entreaties of theater-managers and actors to write again for the stage. In the next fourteen years he published only a half-dozen or more poems, although his name appeared in the list of colaboradores of several papers, among them the Gaceta Literaria, España Literaria, and La América. Apparently his disillusionment was complete. In the Versos a Amalia (La América, Sept. 8, 1858) are these significant lines:
Sonreí de ambición ante la vana
Sombra de mi deseo;
Y al despuntar el sol de mi mañana,
Vi mi horizonte azul (¡que ya no veo!)...
———
Yo fué persiguiendo la límpida estrella
Que allá en lontananza
Resplandece entre todas; aquella
Que deslumbra con locos reflejos,
Que siempre se sigue, que nunca se alcanza.
¡Pérfida estrella de la esperanza
Que alumbra sólo, sólo de lejos!
———
Yo en la mar busqué la gloria
Y de allí torno sin ella.
In September of 1872 Sanz was drawn from his retreat by an appointment to Tangier as Minister Plenipotentiary at a salary of 15,000 pesetas annually. He began his duties in December and continued at his post for exactly a year. Again he pleaded ill health and was granted two months' leave of absence. That he did not return immediately to Madrid is clear from his request of February 12 to be allowed to bring into Cadiz, duty free, a hundred bottles of wine. Early in January, 1873, his appointment to Tangier was confirmed by Amadeo. On the establishment of the republic in February Sanz tendered his resignation, but Castelar himself refused to accept it. In June he finally left his post at Tangier after having been appointed Minister Plenipotentiary to the United States of Mexico. As usual he excused himself on the ground of ill health, and his resignation was accepted in the following September. Sanz certainly could not complain that his merits were unrecognized. In the decree appointing him to the post at Tangier his honors are mentioned as Gran Cruz de la Real y Distinguida Orden de Carlos III, Orden Civil de Maria Victoria, Caballero de la Ínclita de San Juan de Jerusalem, ex Diputado a Cortes.
His movements from this time forward are extremely difficult to follow. In 1878 his name appears in the official list of members of the Asociación de Escritores y Artistas, and his domicile is given as 45 Calle de Atocha. The men that knew him in the closing years of his life agree that he dragged out a miserable existence in the utmost poverty, dependent upon the generosity of his friends. They speak highly of his moral integrity, deploring at the same time the weakness of character which prevented his realizing the promise of his early years. He died April 29, 1881, and was buried in the cemetery of San Lorenzo.