Although The Centaur was Blackwood’s own favorite novel, it is not his most personal. That epithet belongs to The Wave: An Egyptian Aftermath (1916). It is, however, his most religious novel because it comes closest to reflecting his own world belief. It was inspired by Blackwood’s journey through the Caucasus in 1910, a trip that left his spirit so numbed by beauty and vision that for a while he was unable to write. One short story, “Imagination” (Ten Minute Stories, 1914), describes this writer’s block and serves as a preamble to The Centaur in its evocation of the Earth spirit. It was only when Blackwood heard a street musician outside his own London flat—a scene that inspired the conclusion of the novel— that Blackwood’s own spirit was freed and the book began to form.

In The Centaur, Blackwood expresses his view of humanity’s relationship with the world. By using the theories of Gustav Fechner and William James, quotations from whose works head each chapter, Blackwood explores the possibility that Earth is sentient and it is the projection of the Earth-soul that creates visions of creatures of legend (such as centaurs and nymphs) among the psychically sensitive. Civilization has dulled people’s basic senses, which is why so few are aware of the planet’s soul. It is through this exploration of the metaphysical that Blackwood’s book can be regarded as a precursor to modern Magical Realism, because he infuses the world with the power and spirit of Earth’s soul.

The visions that Blackwood sought to explore stretched him to the limits of his narrative power. Language was too blunt an instrument to describe the mystical beauty of spiritual paradise, and there are times when the book becomes too verbose and too cluttered with emotion as Blackwood strives to liberate the reader’s imagination. Near the novel’s climax, after passages of intense vision, Blackwood finds himself having to resort to such ineffective phrases as “he knew all over” and “He knew the Great At-one-ment,” phrases that are inadequate to portray the supremacy of union that O’Malley’s spirit has attained, simply because Blackwood has exhausted all language in reaching this spiritual orgasm. Elsewhere Blackwood captures a vision of intense wonder in the phrase “all the forgotten gods moved forward into life.”

Because The Centaur reflects Blackwood’s own spiritual and mystical experiences in the Caucasus, it is a novel of mystical realism, a forerunner of books by Carlos Castaneda and others. Blackwood was the first great writer to fuse aspects of the mystical, the occult, and pantheism to create works of genuine supernaturalism. Despite the occasional inadequacy of language, which is more the fault of written communication than of Blackwood as Nature’s messenger, The Centaur is the peak of Blackwood’s visionary writing.