If ever a writer was fated to bear a particular name, it was Fernando Pessoa. In Portuguese the word pessoa means “person”; in Latin it means “mask” or “character.” Pessoa spent his life adopting personas, masks, and characters from almost the moment he began his writing career. These alternative personalities were still Pessoa, even when he signed his works under a pseudonym. Many of his alter egos were poets like himself, although only a few were Portuguese. One was an anti-Fascist Italian critic, another a psychiatrist, a third studied engineering; the others included monks, an assistant bookkeeper, a 19-year-old hunchbacked girl who suffered from tuberculosis, a translator of Portuguese literature into English, an inventor and solver of riddles, a French satirist, a toga-wearing lunatic obsessed with Greece who lived in an asylum, and even a Voodooist. As Pessoa explained in 1928, “Pseudonymous works are by the author in his own person, except in the name he signs.” His works were what he called “heteronymous”; they were “by the author” but “outside of his own person. They proceed from a full-fledged individual created by him, like the lines spoken by a character in a drama he might write.” Pessoa’s heteronyms were people with birthdays and deathdays; they had the whole gestalt—passions, fears, dreams, and clearly traced literary paths. As for him, he was a fingidor: a feigner, a pretender, an impostor who believed he could do “more in dreams than Napoleon.”

Did Pessoa truly control his alter egos? Or did his creations, in fact, control him? The layers of identities and personalities that make up Pessoa’s writing career are what draw readers in, and yet they also make it hard at times to have a sense of who he was and what kind of writer he aspired to be. The mystery of Pessoa is at the center of Richard Zenith’s magnanimous new biography, which charts the author’s life as well as the many lives he “performed” as he indulged in repeated “projections, spin-offs, or metamorphoses.” Should we take seriously Pessoa’s claim, which Zenith invites us to question, that “he had no personality of his own, that he was just a ‘medium’ for the many writers who welled up in him and whom he served as ‘literary executor’”? Or, Zenith asks, should we see all of these eccentric scribblers as manifestations of Pessoa and the writer he sought to be—a true “they” inhabiting the “he”?

While scores of writers, from William Butler Yeats to Jorge Luis Borges, used pseudonyms or noms de plume, or else made writers their protagonists or created characters that were manifestations of their alternative personalities, very few have done so to such a degree as Pessoa. His most developed heteronyms were Alberto Caeiro, Ricardo Reis, and Álvaro de Campos, followed by dozens of others like Raphael Baldaya, Vicente Guedes, William Jinks, Devid Merrick, António Mora, Dr. Gaudêncio Nabos, Frederico Reis, Alexander Search, Bernardo Soares, Baron of Teive, António Mora, and Maria José. (Only the last of these was female.) Some wrote in Portuguese, while others delivered their poems, stories, philosophical studies, linguistic theories, self-analysis, automatic writing, or astrological charts in English or French.

It is no secret that Pessoa’s work and that of his fictional writing partners are uneven. Some of his poems are superb. As a prose writer, he can write in a style that is luminous and hypnotizing, but not always. Part of the strangeness of Pessoa’s career is that very few of his writings were published while he was alive. Only one of his books of Portuguese poetry, Mensagem, was published during his lifetime, even if he published much of his English-language poems in chapbooks. His magnum opus, The Book of Disquiet, was published posthumously in 1982 and comprises a galaxy of existential vignettes; Pessoa had left the manuscript in a state of disorder, which was likely not an accident. “To say that this is a book for which no definitive edition is possible,” observes Zenith, who translated it in 2015, “would be a flagrant understatement were it not a conceptually erroneous statement, since there is no ur-book begging for definition.” Instead, what Pessoa had produced was “a quintessential non-book: a large but uncertain quantity of discreet, mostly undated texts left in no sequential order, such that every published edition—inevitably depending on massive editorial intervention—is necessarily untrue to the nonexistent ‘original.’” The same could be said of much of Pessoa’s work, whether poems, stories, philosophical essays, or works of fiction.

Pessoa’s experiments in form and substance were always bold and difficult. They were also not his alone. He was a representative, like Joyce, Proust, Woolf, Kafka, and Musil, of modernism. His unstable personality wasn’t a symptom of schizophrenia but a statement of the anxiety at the heart of the modern sensibility: He was obsessed with being at a time when its meaning had become increasingly transient, precarious, dizzying, unmoored from the absolute truths that had once reigned uncontested. Pessoa’s biggest, most vigorous response to this panoply of apprehensions isn’t, in my view, the writing he channeled but himself—or the selves he articulated—as a creation.

Zenith, himself the owner of a symbolic last name, is a Boswell to Pessoa’s Johnson. At 1,055 pages (the index alone runs for 20 pages, each divided into three columns), his biography, at least a decade in the making, is enviably researched and stylistically nuanced without being obnoxious in its information. In fact, it reads better than most, if not all, of Pessoa’s oeuvre, as if Pessoa had exited the stage so that Zenith would finally be able to narrate his subject’s many personalities and their vicissitudes. There have been, of course, other biographical investigations, among them João Gaspar Simões’s in 1950. Yet no one has produced a richer work, both as a scholar and as a translator, than what Zenith has created here.

When Pessoa died, at the age of 48, he left a huge trunk of manuscripts full of half-baked literary exercises. That, indeed, was his preferred form: He was prone to abandon enterprises midway, to discard projects filled with ambiguities, paradoxes, and inconsistencies, to leave things in a state of incompleteness. It is a tendency that makes him belong, at least tangentially, to the same club as Walter Benjamin, who was also known for his love of fragments, disconnected quotes, and scattered projects. For the biographer, however, this poses a Herculean task: It has taken decades for Zenith to sort through all the manuscripts, in part because only in the last few decades has Pessoa achieved the status of totemic world-class author, which has led not only to his canonization but also to a vast archival enterprise.

Zenith leads the reader commandingly through Pessoa’s house of mirrors. Although his book could be said to be not one biography but many, in order to account for the almost infinite unwrapping of Pessoa’s fictional personas, it is, necessarily, a map of his obsessions as well, though the writer is always seen in his historical, social, and aesthetic context.

In other words, the book is also a narrative of Portugal as a modern nation whose colonial aspirations are coming to an end. We witness the tenuous control of Angola and Mozambique at the end of the 19th century, the democratic First Republic from 1910 to 1926, and, after a coup d’état, the Ditadura Nacional and Estado Novo that followed, orchestrated by the economist António de Oliveira Salazar, who first became a finance minister with sweeping powers in 1928 and then prime minister in 1932. Salazar established a conservative, nationalist political regime that would last, through various incarnations, until the late 1960s and that became known for its acerbic anticommunism and its doctrine of Lusotropicalism, a term coined by Gilberto Freyre to describe imperial rule in the Portuguese colonies.

The political upheavals that shaped Pessoa’s day-to-day life give breadth to Zenith’s story. His superb scholarship follows the emergence and death of each of the heteronyms, which cumulatively gives the impression that we are dealing with a cast of hundreds. It all reads very much like a novel—or several novels tied at the neck.

I first came across Pessoa as a young man in Mexico City, after reading Octavio Paz’s 1961 essay on him, “El desconocido de sí mismo,” which roughly translates as “The Man Who Unknew Himself.” In it, Paz argues that Pessoa, through his artfulness, hid a crucial creative fact that characterized art in general: Artists use their work to find themselves, but seldom reach the right conclusion. Pessoa’s approach was different: He recognized that the self is a void and decided to build a labyrinth around it, a game of mirrors in which the self is multiplied infinitely, thus postponing any concrete answers about what its essence is.

Some may be tempted to compare Pessoa to Borges, who enjoyed his own games with time, the self, and the infinite. Borges’s essay “Borges and I” is an astonishing exercise in self-reconfiguration, in which Borges the person surrenders himself to Borges the author, or maybe the other way around. Yet neither of Borges’s versions of himself can be more dissimilar from Pessoa. Every single line by Borges—even the baroque ones he composed in his youth—seems deliberate, seeking syntactical perfection. Pessoa and his family of half-selves were anything but categorical; instead of revealing themselves in their work, they sought to disappear.

The writer in my view who more closely parallels Pessoa’s capacity to dissolve his own personality in those of his characters is Shakespeare. I don’t intend to belabor here the trope of there having been a non-Shakespeare, as Freud, Henry James, Charlie Chaplin, Daphne du Maurier, and Helen Keller have suggested at various times. But what I think Shakespeare and Pessoa have in common is their dedication to character creation: Each produced a miscellany of heroes and villains, all with their own complex and contradictory inner universes. But more than that: Like Shakespeare’s characters, Pessoa’s were in many ways aspects of himself; to create them, he had to explore the very depths of his being.

To tell the life of any person takes more than patience. It requires sacrifice—the biographer must live vicariously through his subject. In reading Pessoa, I frequently had the impression that Zenith, to offer that much detail, had to disappear, to become Pessoa for a time. He divides the book into four parts. The first tells the story of Pessoa’s early life. He was born in Lisbon in 1888 to a middle-class family. He lost his father at the age of 5 and soon after a brother, and by 1895 his mother had remarried a ship captain who was later named Portugal’s consul in Durban, the capital of the British colony of Natal (later South Africa)—where, as it happens, Mahatma Gandhi was also living at the time. Pessoa and his mother followed the ship captain to Natal, where Pessoa attended the University of the Cape of Good Hope before returning to his native Lisbon in 1905.

In these early years, Pessoa took an interest in writing and created several of his best-known heteronyms: Ricardo Reis, who was supposedly born a year before Pessoa (José Saramago, the Portuguese Nobel Prize winner for literature in 1998, wrote the novel The Year of the Death of Ricardo Reis focused exclusively on him); Alexander Search, who emerged as a writer of poems, essays, and stories in 1906; and Alberto Caeiro, whose first poems appeared in 1914, a couple of months before the appearance of yet another heteronym, Álvaro de Campos, and the initial odes of Reis. The beginnings of Pessoa’s multilingualism (he knew French, English, and Spanish as well as Portuguese) stem from this period. It might be argued that the unfolding of alter egos was an unwrapping of tongues. That’s what happens to polyglots: Different languages give place to a throng of personalities.

By 1918, Pessoa started publishing chapbooks of his English poems, which were favorably reviewed in the British press. This led him to the belief that he might be a successful publisher. His adventures on this front were disastrous. Of course, a disaster is sometimes more valuable than a triumph. For a while, Pessoa seemed to be constantly engaged in failed businesses, such as the publishing house Olisipo, founded in 1921, using family money without acknowledging his debt, and escaping all sorts of complicated personal situations that forced him to move from one apartment to another. Pessoa’s Luftmensch-like life—tottering, embarking on one quixotic endeavor after another—was often that of a loner, although he was in love with a secretary, Ophelia Queiroz, but the relationship never quite reached consummation.

Pessoa’s politics are hard to pin down. At times, as Zenith portrays him, he appears to have embraced the new right-wing politics that defined Salazar’s Portugal and also Germany under Hitler. Yet these loyalties also seem feeble. At best, Pessoa was wishy-washy, switching ideological modes and psychological moods with equal ease. What is most relevant is that he was interested in occult topics: cabala, Rosicrucians, mysterious objects, spiritism, concocting lines of communication with specters whose cockamamie notions he and a few of his heteronyms adopted as a kind of creed. He had an obsession with symbols, linguistic formulas, conspiracies, mind reading, and clairvoyance. And he believed that all reality is dual in nature and that aspects of the world were only accessible to an elite group of people initiated in special practices.

This, to me, is Pessoa’s most decisive side: his belief in supernatural forces. His support for certain fascist ideas was a symptom of his conviction that inner forces rule us and that, as a result, free will is sheer fiction. In his poetry, he articulated the conviction that spirits would visit him, a symphony of them, that he as a writer died in his own work. “I no longer include me in myself,” he wrote in the poem “The Mommy,” written in 1914. The various spirits had their own ideological systems, at times in opposition to Pessoa’s.

Among Pessoa’s most disturbing facets were his brushes with anti-Semitic texts as well as fascism. Again, Zenith, adoring as he is of his subject, walks a delicate line on this topic, though he does not flinch from confronting this aspect of Pessoa’s writings. Under the aegis of Olisipo, Pessoa entertained the idea of publishing, in Portuguese translation, The Protocols of the Elders of Zion, a nefarious, fraudulent document that first circulated in Russia and purported to show that a global Jewish cabal was intent on controlling governments, business, and the media. Pessoa commissioned someone with the initials A.L.R., a writer about whom nothing else is known, to do the translation. In the end, nothing came of it.

The episode, however, was only one in a series in which Pessoa toyed with xenophobic, jingoistic literature, such as a booklet called The Interregnum, in which he defended military dictatorship as advisable for Portugal to find political stability. Yet part of Pessoa’s mystery is that he was also said to be a direct descendant of Jews, and among his publishing adventures, he planned to issue a pamphlet—in Portuguese, English, and French—titled The Jew Sociologically Considered, because, in his view, Jewish themes were not sufficiently pondered in Portugal. The pamphlet never materialized either. If it had, it is possible it might have been anti-Semitic.

Arguably, Pessoa’s golden period as a writer started in 1927, thanks to his collaboration with the arts and literary review Presença. His best work was produced in this period, including some of the most inspired passages of The Book of Disquiet, published in periodicals between 1929 and 1932. A few of his poems were translated into French, and his book Mensagem—the only volume of his Portuguese poetry to appear during his lifetime—was released in 1934. He was experiencing the type of success he had dreamed of for a long time. But this success was short-lived: In November 1935, he suffered from abdominal pain, was interned at a hospital in Lisbon, and died, likely of intestinal obstruction. His last words were in English: “I know not what to-morrow will bring.” At the time of his burial, in Lisbon’s Prazeres Cemetery, Pessoa was largely unknown, and so were his imaginary cohorts. In 1985 he would be disinterred, his remains set to rest in the nation’s prime holy ground, the Cloister in the Jerónimos Monastery. It is fitting that he felt a kinship with Walt Whitman, whom, according to Zenith, Pessoa discovered in 1907 and “hardly knew how to react.”

“Song of Myself” (1855), in its vision, is Pessoan. Or perhaps more accurately, Pessoa was Whitmanian. Whitman’s straightforward exuberance was the opposite of Pessoa’s baroque disguises. Still, Whitman—himself a larger-than-life personality—was delighted, as he put it, to resist any effort at being constrained. The same is true of Pessoa.