A Voyage to Arcturus is a novel by the Scottish writer David Lindsay, first published in 1920. An interstellar voyage is the framework for a narrative of a journey through fantastic landscapes. The story is set at Tormance, an imaginary planet orbiting Arcturus, which in the novel is a binary star system, consisting of the stars Branchspell and Alppain. The lands through which the characters travel represent philosophical systems or states of mind as the main character, Maskull, searches for the meaning of life. The book combines fantasy, philosophy, and science fiction in an exploration of the nature of good and evil and their relationship with existence. Described by critic, novelist, and philosopher Colin Wilson as the "greatest novel of the twentieth century", it was a central influence on C. S. Lewis' Space Trilogy, and through him on J. R. R. Tolkien, who said he read the book "with avidity". Clive Barker called it "a masterpiece" and "an extraordinary work ... quite magnificent".

The book sold poorly during Lindsay's lifetime, but was republished in 1946 and many times thereafter. It has been translated into at least six languages. Critics such as the novelist Michael Moorcock have noted that the book is unusual, but that it has been highly influential with its qualities of "commitment to the Absolute" and "God-questioning genius".

David Lindsay was born in 1876. His father was a Scottish Calvinist and his mother English. He was brought up partly in London and partly in Jedburgh in the Scottish borders. He enjoyed reading novels by Walter Scott, Jules Verne, Rider Haggard and Robert Louis Stevenson. He learnt German to read the philosophical work of Schopenhauer and Nietzsche. He served in the army in the First World War, being called up at age 38. He married in 1916. After the war ended in 1918, he moved to Cornwall with his wife to write. Lindsay told his friend E. H. Visiak that his greatest influence was the work of George MacDonald.

Tormance is a planet orbiting the double star Arcturus, consisting of Branchspell, a large yellow sunlike star, and Alppain, a smaller blue star 100 light years from Earth. The light of the second sun, Alppain, is to the north; southern countries are illuminated only by Branchspell. Maskull, longing for adventures, accepts an invitation from Krag, an acquaintance of his friend Nightspore, to travel to Tormance after a séance. The three travel to an abandoned observatory at Starkness in Scotland, where there is a tower with Tormance's heavy gravity; climbing it is difficult. Maskull learns he will not return from the voyage. They set off in a "torpedo of crystal" from the top of the tower, propelled by Arcturian "back rays".

Maskull awakens to find himself alone in a desert on Tormance; his body has grown a tentacle or magn from his heart, and an organ called a breve. A woman, Joiwind, exchanges blood with him to allow him to survive on Tormance; she tells him that Surtur created everything. She worships Surtur. Her husband Panawe suggests that Maskull may have stolen something from the Maker of the universe, to ennoble his fellow creatures. Maskull travels to the Lusion Plain, where he meets Surtur. Surtur asserts the beauty of his world, claims Maskull is there to serve him, and disappears. Maskull meets a woman, Oceaxe, from Ifdawn, who has a third arm in place of her magn. She is rude, but shows interest in having him as lover, and gives him a red stone to convert his magn into a third arm. Maskull wakes to find his magn transformed into a third arm, which causes lust for what is touched, and his breve changed to an eyelike sorb which allows dominance over the will of others. He travels through Ifdawn with Oceaxe; she wants him to kill one of her husbands, Crimtyphon, and take his place. Maskull is revolted at the idea, but kills Crimtyphon when he sees him using his will to force a man into becoming a tree. Tydomin, another wife of Crimtyphon's, uses her will to force Oceaxe to commit suicide by walking off a cliff; she persuades Maskull to come to her home in Disscourn, where she will take possession of his body. On the way they find Joiwind's brother Digrung who says he will tell Joiwind everything about Maskull's behavior on Tormance; to prevent this, and encouraged by Tydomin, Maskull absorbs Digrung, leaving his empty body behind. At Tydomin's cave, Maskull goes out of his body to become the apparition that appeared at the seance where he met Krag. He awakens free of her mental power.

Maskull takes Tydomin to Sant, to kill her. On the way they meet Spadevil, who proposes to reform Sant by amending Hator's teaching with the notion of duty. He turns Maskull and Tydomin into his disciples by modifying their sorbs into twin membranes called probes. Catice, the guardian of Hator's doctrine in Sant, and who has only one probe, damages one of Maskull's to test Spadevil's arguments. Maskull accepts Hator's ideas and kills Spadevil and Tydomin. Catice sends Maskull away to the Wombflash Forest, in search of Muspel, their home. Maskull awakes in the dense forest with a third eye as his only foreign organ, hears and follows a drumbeat, and meets Dreamsinter, who tells him that it was Nightspore whom Surtur brought to Tormance and that he, Maskull, is wanted to steal Muspel-light. Maskull travels to the shore of the Sinking Sea, from which Swaylone's Island can be seen. There he meets Polecrab, a fisherman, who is married to Gleameil. Maskull goes to Swaylone's Island, where Earthrid plays a musical instrument called Irontick by night; no one who hears it ever returns. Maskull is accompanied by Gleameil, who has left her family. Attracted by the music, she dies. Maskull, after entering a trance, forces Earthrid to let him play the instrument, whereupon Earthrid dies and Irontick is destroyed. Maskull crosses the sea by manoeuvring a many-eyed tree and reaches Matterplay, where many life-forms materialise alongside a magical creek and vanish before his eyes. He goes upstream and meets Leehallfae, an immensely old being of a third sex, who seeks the underground country of Threal where the god Faceny may dwell. They reach Threal through a cave. Leehallfae falls ill and dies. Corpang appears and says this is because Threal is not Faceny's world, but the creator of the world of feeling, Thire's. Corpang follows Maskull to Lichstorm, where they again hear drumbeats.

Maskull and Corpang meet Haunte, a hunter who travels in a boat that flies thanks to masculine stones which repel earth's femininity. Maskull destroys the masculine rocks which protected Haunte from Sullenbode's femininity, and all three journey to her cave. Sullenbode, a faceless woman, kills Haunte as they kiss. Maskull and Sullenbode desire each other. Maskull, Sullenbode and Corpang set off. Corpang goes eagerly ahead but Maskull pauses, causing Sullenbode to die. Maskull, upon waking, discovers Krag again, and then Gangnet. They travel together to the ocean and take to the sea on a raft. When the sun Alppain rises, Maskull sees in a vision Krag causing the drumbeat by beating his heart, and Gangnet, who is Surtur, dying in torment enveloped by Muspel-fire. Maskull learns that he is in fact Nightspore himself, and dies. Krag tells Nightspore he is Surtur, known on Earth as pain; and teaches him about the origin of the Universe.

Methuen agreed to publish A Voyage to Arcturus, but only if Lindsay agreed to cut 15,000 words, which he did. These passages are assumed lost forever. Methuen also insisted on a change of title, from Lindsay's original (Nightspore in Tormance), as it was considered too obscure. Of an original press run of 1430 copies, no more than 596 were sold in total. The novel was made widely available in paperback form when published as one of the precursor volumes to the Ballantine Adult Fantasy series in 1968, featuring a cover by the illustrator Bob Pepper.

Editions of A Voyage to Arcturus have been published in 1920 (Methuen), 1946 (Gollancz), 1963 (Gollancz, Macmillan, Ballantine), 1968 (Gollancz, Ballantine),1971 (Gollancz), 1972, 1973, 1974 (Ballantine), 1978 (Gollancz), 1992 (Canongate), 2002 (University of Nebraska Press), and later by several other publishers. It has been translated into at least six languages.

Lindsay's choice of title (and therefore the setting in Arcturus) may have been influenced by the nonfictional A Voyage to the Arctic in the Whaler Aurora (1911), a book by his namesake, David Moore Lindsay about the ship SY Aurora. The scholar Kathryn Hume writes that with the name of the planet, Tormance, and its sun, Alppain, Lindsay "is cosmically punning on the yogic tenet that all existence, all consciousness, is pain". The historian Shimon de Valencia states that the names "Surtur" and "Muspel" are taken from Surtr, the lord of Múspellsheimr (the world of fire) in Norse mythology.

The novel is recognised for its strangeness. Tormance's features include its alien sea, with water so dense that it can be walked on. Gnawl water is sufficient food to sustain life on its own. The local spectrum includes two primary colours unknown on Earth, ulfire and jale, and a third colour, dolm, said to be compounded of ulfire and blue. The sexuality of the Tormance species is ambiguous; Lindsay coined a new gender-neutral pronoun series, ae, aer, and aerself for the phaen who are humanoid but formed of air.

Hume writes that the book evidently has a deeper meaning, which may be strictly allegorical or more broadly "visionary" like the work of William Blake; and that this has both attracted a cult following, and prevented the book from reaching a wider audience. Hume describes the planet of Arcturus, far from being a standard science fiction setting, as having a threefold function: the literal setting for a "quest romance"; the psychological frame, "a projection of the faculties of the mind"; and an allegorical paysage moralisé, like the moralised landscapes of Pilgrim's Progress or Piers Plowman.

Hume contrasts A Voyage to Arcturus with Christian allegory, which, she writes, makes its direction and plan clear to the reader. She gives as one example the seven circles of Dante's 14th century Inferno, which are organised by the seven deadly sins. She notes, too, that readers readily see in Maskull's steady journey through many challenges a reflection of John Bunyan's The Pilgrim's Progress (1678) in which Pilgrim journeys continuously through the trials of the world towards salvation. Lindsay's "original allegory" has its own framework, which is the hierarchy of experiences on the road to enlightenment, from Pleasure to Pain, Love, Nothing, and finally Something. This structure is compounded by having the protagonist examine the world in terms of the dyad of I and not-I, and the triad of "material creation, relation, and religious feeling"; in the end, Maskull transcends personality for dualism on both the macrocosmic and the microcosmic scales.

The critic and philosopher Colin Wilson described A Voyage to Arcturus as the "greatest novel of the twentieth century". The playwright and novelist Clive Barker stated that "A Voyage to Arcturus is a masterpiece", calling it "an extraordinary work ... quite magnificent." The fantasy author Philip Pullman named it for The Guardian as the book he thought was most underrated.

Reviewing the book in 2002, the novelist Michael Moorcock asserted that "Few English novels have been as eccentric or, ultimately, as influential". He noted that Alan Moore, introducing the 2002 edition, had compared the book to John Bunyan's Pilgrim's Progress (1678) and Arthur Machen's The Great God Pan (1890), but that it nevertheless stood "as one of the great originals". In Moorcock's view, although the character Maskull seems to be commanded to do whatever is needed to save his soul, in a kind of "Nietzschean Pilgrim's Progress", Lindsay's writing does not fall into fascism. Like Hitler, Moorcock argued, Lindsay was traumatised by the trench fighting of the First World War, but the "astonishing and dramatic ambiguity of the novel's resolution" makes the novel the antithesis of Hitler's "visionary brutalism". Moorcock noted that while the book had influenced C. S. Lewis's science fiction trilogy, Lewis had "refused Lindsay's commitment to the Absolute and lacked his God-questioning genius, the very qualities which give this strange book its compelling, almost mesmerising influence."

Also in 2002, Steven H. Silver, criticising A Voyage to Arcturus on SF Site, observed that for a novel it has little plot or characterisation, and furthermore that it gives no motives for the actions taken by its characters. In his view, the book's strength lay in its "philosophical musings" on humanity after the First World War. Silver compared the book not with later science fiction but with the earlier authors H. G. Wells and Jules Verne, commenting however that Lindsay had "neither author's prose skills." He suggested that Lindsay was combining philosophy with an adventure tale in the manner of Edgar Rice Burroughs.

The novel was a central influence on C. S. Lewis's 1938–1945 Space Trilogy; he called A Voyage to Arcturus "shattering, intolerable, and irresistible". Lewis also mentioned the "sorbing" (aggressive absorption of another's personality into one's own, fatal to the other person) as an influence on his 1942 book The Screwtape Letters. Lewis in turn recommended the book to J. R. R. Tolkien, who said he read it "with avidity", finding it more powerful, more mythical, but less of a story than Lewis's Out of the Silent Planet; he commented that "no one could read it merely as a thriller and without interest in philosophy[,] religion[,] and morals". Tolkien, who used frame stories in his novels, did not approve of the frame story machinery, the back-rays and the crystal torpedo ship, that Lindsay had used; in his unfinished novel The Notion Club Papers, Tolkien makes one of the protagonists, Guildford, criticise those kinds of "contraptions".

In 1984, the composer John Ogdon wrote an oratorio entitled A Voyage to Arcturus, based on Lindsay's novel and biblical quotations. Ogdon's biographer, Charles Beauclerk, notes that Lindsay was also a composer, and that the novel discusses the nature and meaning of music. In Beauclerk's view, Ogdon saw Lindsay's novel as a religious work, where for instance the wild three-eyed, three-armed woman Oceaxe becomes Oceania, described in the Bible's Book of Revelation chapter 12 as "a woman cloth'd with the sun, and the moon under her feet".

The BBC Third Programme presented a radio dramatisation of the novel in 1956. Critic Harold Bloom, in his only attempt at fiction writing, wrote a sequel to this novel, entitled The Flight to Lucifer. Bloom has since critiqued the book as a poor continuation of the narrative. William J. Holloway, then a student at Antioch College in Yellow Springs, Ohio, created a 71-minute film adaptation of the novel in 1970. The film, unavailable for many years, was independently restored, re-edited and colour-enhanced, to be redistributed on DVD-R in 2005. In 1985, a three-hour play by David Wolpe based on the novel was staged in Los Angeles. Paul Corfield Godfrey wrote an operatic setting based on the novel to a libretto by Richard Charles Rose; it was performed at the Sherman Theatre Cardiff in 1983. The jazz composer Ron Thomas recorded a concept album inspired by the novel in 2001 entitled Scenes from A Voyage to Arcturus. The Ukrainian house producer Vakula (Mikhaylo Vityk) released an imaginary soundtrack called A Voyage To Arcturus as a triple LP in 2015. A musical based on the novel was written by Phil Moore and performed in 2019 at the Peninsula Theatre, Woy Woy, Australia. This production was filmed and is available on some streaming platforms.

• 1920 in science fiction

• Lindsay, David (1920). A Voyage to Arcturus. Methuen. OCLC 606220214.

• A Voyage to Arcturus at Standard Ebooks

• A Voyage to Arcturus at Project Gutenberg
• A Voyage to Arcturus public domain audiobook at LibriVox