"The history of literature contains some faint parallels to his performance of multiple authorship. William Butler Yeats created Michael Robartes and Owen Hearne, a duo of “collaborators” with contrasting personalities. The Spanish poet Antonio Machado (1875–1939) also signed some of his poems and prose pieces with the names of two alter egos: Juan de Mairena and Abel Martín, who was Mairena’s “master.” But no writer can rival Pessoa’s achievement of configuring, through his heteronyms, radically different poetic and philosophical attitudes that formed a glorious if not always harmonious musical ensemble." Richard Zenith Lithub