Philippine historians regard López Jaena, along with Marcelo H. del Pilar and José Rizal, as the triumvirate of Filipino propagandists. Of these three ilustrados, López Jaena was the first to arrive in Spain and may have begun the Propaganda Movement, which was a movement based in Spain that advocated the reform of the then-Spanish colony of the Philippines and which eventually led to the armed Philippine Revolution that begun in Manila in 1896. The Propaganda Movement was a key step towards a Philippine national identity.
His parents sent López Jaena to Jaro to study at St. Vincent Ferrer Seminary which had been opened under the administration of Governor General Carlos María de la Torre y Nava Cerrada. While there, he served as a secretary to an uncle, Claudio López, who was the honorary vice consul of Portugal in Iloilo. His ambition to become a physician convinced his parents that this was the better course of action.
López Jaena sought enrollment at the University of Santo Tomas but was denied admission because the required Bachelor of Arts degree was not offered at the seminary in Jaro. Instead he was appointed to the San Juan de Dios Hospital as an apprentice. Unfortunately, due to financial problems, he dropped out and returned to Iloilo to practice medicine.
During this period, his visits with the poor began to stir feelings about the injustices that were common. At the age of 18 he wrote the satirical story "Fray Botod" which depicted a fat and lecherous priest. Botod’s false piety "always had the Virgin and God on his lips no matter how unjust and underhanded his acts are." This incurred the fury of the friars. Although the story was not published, a copy circulated in Iloilo but the friars could not prove that López Jaena was the author.
He got into trouble for refusing to testify that certain prisoners died of natural causes when it was obvious that they had died at the hands of the mayor of Pototan. López Jaena continued to agitate for justice and finally went to Spain when threats were made on his life. López Jaena sailed for Spain in 1879. There he became a leading writer and speaker for Philippine reform.
López Jaena pursued his medical studies at the University of Valencia but did not finish. Once Rizal reproached Lopéz Jaena for not finishing his medical studies. Graciano replied, "On the shoulders of slaves should not rest a doctor's cape." Rizal countermanded, "The shoulders do not honor the doctor's cape, but the doctor's cape honors the shoulders."
He then moved to the field of journalism. Losing interest in politics and academic life, he soon enjoyed his life in Barcelona and Madrid. However, his friends forgave him these indiscretions due to his talent with words. Mariano Ponce who was another of the Filipino propagandists in Spain observed, "... a deafening ovation followed the close of the peroration, the ladies waved their kerchiefs wildly, and the men applauded frantically as they stood up from their seats in order to embrace the speaker." Rizal noted, "His great love is politics and literature. I do not know for sure whether he loves politics in order to deliver speeches or he loves literature to be a politician."
In addition he is remembered for his literary contributions to the propaganda movement. López Jaena founded the fortnightly newspaper, La Solidaridad. When the publication office moved from Barcelona to Madrid, the editorship was succeeded to Marcelo H. del Pilar. His talent can be seen in the publication Discursos y Artículos Varios (Speeches and Various Articles).
López Jaena died of tuberculosis on January 20, 1896, eleven months short of his 40th birthday. The following day he was buried in an unmarked grave at the Cementerio del Sub-Oeste of Barcelona. He died in poverty.
His death was followed by Marcelo H. del Pilar's on July 4 and on December 30 by José Rizal's by firing squad, thus ending the great triumvirate of propagandists. His remains have not been brought back to the Philippines.