He was born in the city of Três Rios / RJ on 09/27/1958. At the age of 14, he met Spiritism through his brother, the eldest of the family, who invited him to attend study groups at the GEFE – “Grupo Espirita Fé and Esperança.” From this date on, he immersed himself deeply in the study of Spiritism.

He read several Spiritist writers and as a researcher he witnessed and participated in various groups that studied mediumistic phenomena, knowing that this experience would be important for his reasoned faith in his life of study and research. And it was in the deepening of the works and thinking of Allan Kardec that he found answers to his deepest inquiries and his objects of study in the years to come.

Besides reading and knowing all the works written by Kardec, he immersed himself in the collection indicated by Kardec in his "Rational Catalog", a repertoire of works against and in favor of Spiritism, which demonstrates all the coherence and the good sense of Kardec, as educator in the freedom of the formation of thinkers of Spiritism.

Cosme Massi is also a scholar of the classical philosophers who composed Allan Kardec's thought until the nineteenth century: Plato, Aristotle, Epicurus, Saint Augustine, Immanuel Kant, René Descartes, Blaise Pascal, David Hume and others.

With his more than 30 years of studies in logic, epistemology, physics and Spiritist science, he affirms that among all the authors, no set of works was as simple, profound, logical and coherent as that of the thinker and creator of Spiritism: Allan Kardec.