Mariano attended Universidad Central in Caracas, Venezuela.
Mariano attended Universidad Central in Caracas, Venezuela and Universidad de Chile. He received degree in history in 1923 and doctorate in 1928.
Among Mariano's books, his collection of essays on history, literary criticism, and cultural history are remarkable. He traveled a lot through the Americas. His work is also important because of his wide perspective, studying the culture of the entire continent. He left Venezuela, under the political persecution of dictator Juan Vicente Gómez. Living for a large period in Chile, he studied history, gaining the degree of “Profesor de Historia” and later a doctorate in philosophy and letters.
He came back to Venezuela in 1936, working as a professor and author. He founded the Asociación de Escritores de Venezuela (Writers Association from Venezuela), and worked for the Ministry of Education. He taught at Columbia University, New York.
He died in Caracas on January 1, 1965.
Mariano was twice married, first to a Chilean lady, Isabel Cento, with whom he had his only daughter, named Delia Isabel Picón de Morles. He later married Venezuelan Beatriz Otánez.