4 1Guillermina Massanet Rivera-Fermaintt was without a doubt, in the last century, the most important name of Spiritism, in Puerto Rico; which has highlighted its dedication to the understanding of Spiritism with characteristics more faithful to the work of Allan Kardec.

Born in 1894, in the village of Arroyo, Guillermina, still young, moved to live in the capital city of San Juan, in order to complete her studies. Graduated in Teaching at the University of Puerto Rico, she dedicated to the career of professor for many years. Among Puerto Rican society, she was also known for its participation in social and cultural actions. As for her personal life, she married Benigno Fermaintt, from whose marriage three children were born.

Her important contributions in the Puerto Rican spiritist movement led her to occupy, in 1946, during the administration of Luis Sánchez, the position of vice president of the Federation of Spiritists of Puerto Rico (FEPR).

In the same year, Sánchez and Guillermina were present at the 1st Pan-American Spiritist Congress, held in Buenos Aires, Argentina; which is the year when the CEPA (Pan-American Spiritist Confederation) was founded, making the adhesion of the FEPR's to the new international organization an official one. After a brief period, after the resignation of Sánchez, Guillermina assumed the presidency of the FEPR, whose position she occupied until 1970.

In 1957, she became the first woman to be elected president of CEPA, assuming the mandate until 1960.

In assuming this presidency, Guillermina found an institution divided between those who agreed and those who were against the definition of an eminently scientific and non-religious Spiritism, a position adopted by CEPA in previous years. Seeking a unity and a conciliatory tone, her administration was marked by the elaboration of a new statute that diminished the differences.

Later, in 1969, Guillermina acted as president of the VIII Pan-American Spiritist Congress, held in the Puerto Rican capital of San Juan.

In 1977 Guillermina, accompanied by other women, toured the entire territory of Puerto Rico, visiting various spiritist societies, seeking support and contribution for the founding of the Asociación de Mujeres Espiritistas Puertorriqueñas en Acción (AMEPA). Her task was a success and on March 17, 1977, AMEPA was founded, being elected its first president.

Her return to the spiritual homeland took place in 1984, when she was 90 years old.

For her contribution to the development of a lay and freethinking Spiritism, Guillermina was always remembered on several important occasions in the history of CEPA. In 2008, for example, the Organizing Committee of the XX Pan-American Spiritist Congress, held in Puerto Rico, decided to dedicate the event to her memory. The current president of CEPA (now the International Spiritist Association), Jacira Jacinto da Silva, also emphasized recalling her significant role, in an article published in the "Spiritist America" newspaper, in its June 2016 edition.

The importance of the dissemination of Spiritism, in its true nature, protected by the Kardecist codification, free of syncretism and mystification, as a necessary factor for its survival, was the great contribution of Guillermina Massanet de Fermaintt to the Puerto Rican and Latin American spiritist movement.