People always ask where the ideas for books come from, and it’s usually a hard question to answer. Books don’t have just one idea, and the process of writing is an iterative one in which ideas come and go and don’t work out the way you initially expect. But I can identify at least one of the starting places for the current book.

I was sitting up at night feeding a baby and trying to read, and in a vague and sleepless way I was kicking around a half-dozen ideas for a new book, something science-fictional, or possibly some sort of Magical London Fantasy, why not, something with dueling occultists, when (in Alexandra Owen’s magnificent history The Place of Enchantment: British Occultism and the Culture of the Modern, which I had picked up for research on the latter idea) I read this beautiful sentence: “In September 1898 two respectable Victorians met in a private house in London for the express purpose of traveling to the planets.”

Well. Did they now.

Sort of. Their names were Frederick Leigh Gardner and Annie Horniman. Gardner was a stockbroker and second-generation spiritualist, and later an antiquarian bookseller; Horniman was a patron of the arts who founded and managed theatres in Dublin and Manchester. They were, like many late Victorian occultists, quite serious people with advanced intellectual interests and a range of worthwhile activist causes. They were also Second Order Adepts of the Golden Dawn—the elite occult order that around this time was admitting Aleister Crowley. During their interplanetary travels, they went by the magical names “Fortiter et Recte” and “De Profundis Ad Lucem.”

Over the course of 1898, F.E.R. and D.A.L. traveled to Mercury, Venus, Mars, Jupiter, and Saturn. They traveled by means of astral projection, by an exercise of the will, through a heaven of rays of light and hexagrams and angelic guardians of the gates. They took detailed notes of their observations. On Saturn they met a winged and armored man, who introduced them to his “old and dying world.” On Jupiter they found “a greyness of dust and cobwebs” and “a strong atmosphere of illusion.” When they visited the Sun they encountered an impassible barrier to further astral travel: an “unbearable light,” and heart palpitations.

I had an organizing idea for my book; a central image, and the start of a sense of a larger world around it.

An account of a 1900 trip to Mars, under the supervision of Soror Deo Date (Dorothea Hunter), gives a sense of Gardner and Horniman’s mode of travel:

On Thursday, 20th December, 1900, Soror Deo Date and a group of students met at 36 B[lythe] R[oad] in order to investigate clairvoyantly the symbolism of the Sword. We sat in a semi-circle at the north side of the Altar, facing the South, when Mars was in Virgo at the time. Deo Date then made the Invoking Hexagrams of Mars round the room […] We then mentally formulated the Hexagram of Mars in red light at that point of the compass. The upper triangle appeared flaming, and an armed figure of somewhat earthly type appeared to look through it. […] We did not stop to examine this figure much, but went through the Hex, astrally, and found ourselves in a region of flames [where] a gigantic, mail-clad Angel appeared, with winged helmet, and great flame-coloured wings from his shoulders. There was some diversity of opinion concerning his sword. […] Then we vibrated the Names and rose in what we thought at first was a blade-shaped shaft of White Light. . . We seemed to have been led through the path of Mars on to a solar plane. All the planets are but rays, or differentiations of the Sun, it is true, but some special teaching was evidently to be given us by this abrupt transition from Mars.

The full account of this journey is in R.A. Gilbert’s The Golden Dawn: Twilight of the Magicians, as Appendix F. The magicians in my book travel by a similar method, but I had to streamline it a bit, for plausibility.

Did they really believe they were traveling to the planets? In what sense “traveling,” in what sense “real,” in what sense “planets”? I knew that my book would be a fantasy, and the rules of physics would be for grabs; but I had to know what contemporaries thought was conceivable, and just as importantly how they might talk to each other about it. Their writings play this stuff straight, and are detailed, intelligent, scientifically precise. Did they think they were actually visiting Mars—the real big ball of rock in the sky—and encountering its inhabitants? Or that they were in some sense traveling in spiritual dimensions, in alternate but actual states of being, and encountering spirits and angels, who merely took the form of Martians? Or was this a sort of psychological experiment, an examination of the magician’s own soul and subconscious by means of the symbolism of the planets?

In the specific case of Horniman and Gardner, probably mostly the latter. Initiates of the Golden Dawn were not your average followers of fin de siècle Victorian occult fashion; they were at the high end of the range of intellectual sophistication, and rather looked down on vulgar table-rappers and spoon-benders who took things too literally. On the other hand there certainly were contemporaries who did believe in space travel through clairvoyance—quite a lot of them.

Astronomy and the occult were both hugely fashionable in the latter part of the Victorian era. There were any number of societies devoted to the study of the paranormal: from suburban mediums and their neighbors to trans-Atlantic organizations; from arcane and mystical orders to self-consciously scientific outfits devoted to the study of true psychic phenomena and the debunking of superstition. Meanwhile “learn’d astronomers […] lectured with much applause,” and got on the covers of magazines. Popular Astronomy magazine recorded the activities and discoveries of amateur astronomers from London to Salt Lake City. In London, Sir Robert Ball delivered popular lectures under romantic titles like In Starry Realms and Time and Tide: A Romance Of the Moon. In New York in 1895, Mary Proctor described lecturing on astronomy to “positively the roughest crowd,” a crowd of eight hundred of “the very poorest [who] must have felt a longing to know a little more about the wonders of the heavens … standing room was at a premium [and] I saw several policemen scattered here and there.”

Mars was central—it exerted, as John Carter put it, “a spell of overpowering fascination.” Popular interest in astronomy received a huge boost after the 1877 Great Opposition, during which the Italian astronomer Giovanni Schiaparelli observed “canali”—long straight markings, or channels—on the Martian surface; other astronomers quickly translated canali as canals and decided that they were evidence of civilization. The idea of civilization on Mars—advanced, ancient, master of its alien environment—was taken very, very seriously. Many astronomers continued to insist that Schiaparelli’s markings were in fact imaginary (illusions created by an overactive pattern-seeking imagination, smudges on the lens, shadows of the veins in the observer’s own eyeball…) but for decades it seemed that the pro-Martian side was winning at least the popular argument. The New York Times, in 1909, declared that “Save the problem of immortality and of life beyond the grave, there is, perhaps, no more fascinating one than that which conjectures life on Mars and the possibility of establishing communication with that great planet.”

As the Times’ list of problems suggests, astronomy and the paranormal were oddly closely linked in the late Victorian mind. The paranormal presented itself as a new scientific field of study, at a time when the concept of professional scientific disciplines as we understand them today was still somewhat new; even the most arcane and antiquarian occultists could describe what they were doing as research or science. On the other hand the study of astronomy—the heavens—alien life—was literally an unearthly one; as the astronomer Agnes Clerke put it, “[t]he physics of the heavenly bodies […] deals with transcendental conditions, and what is strange to terrestrial experience may serve admirably to expound what is normal in the skies.”

(Around the same time that the Golden Dawn’s members were clairvoyantly visiting the planets, the Theosophist Annie Besant was conducting a series of observations of atomic chemistry by means of microscopic clairvoyance. But astronomy is what I’m interested in here.)

The two most famous popularizers of the belief in an inhabited Mars, Camille Flammarion and Percival Lowell, both mixed their astronomical interests with research into the paranormal. Lowell, whose Flagstaff Observatory in Arizona produced the definitive photographs of the canals, was a paranormal researcher before he was an astronomer; he was a materialist and a debunker, whose book Occult Japan attempted to provide a psychological and material explanation for accounts of divine possession.

Flammarion was more mystically inclined than Lowell; he considered “the earths which hover in space” to be “the future regions of our immortality […] a celestial home of many dwellings […] schools where the expanding soul progressively learns and develops.” His writings alternate between authoritative scientific treatises like La planète Mars, and mystical quasi-fictions; like Lumen, or Uranie, in which his hero “Camille” accompanies the muse of astronomy on a tour of the heavens; his account of Mars and Martian civilization is interspersed with “authentic accounts” of telepathy, mesmerism, and communications with the dead. “These are facts!,” he declares, rapping the reader’s knuckles a bit. “[T]he separation which seems to exist between the Earth and the Moon,” he argues, “or between the Earth and Mars, or even between the Earth and Sirius, is only an illusion due to the insufficiency of our perceptions…”

In later life, Flammarion became the president of the international Society for Psychical Research; in his inaugural address he stated bluntly that “Telepathy is as much a fact as are London, Sirius and oxygen.”

There was a lot of this sort of stuff, and thanks to the miracle of Project Gutenberg much of it is preserved in the ether, easily accessible if, like me, you become irrationally obsessed with it in the middle of the night. From the 1880s up to the First World War, Martian spirits seem to have been in regular communication with earthly mediums. In 1886, Marie Corelli kicked off her bestselling career with A Romance Of Two Worlds, in which her heroine meets the angel Heliobas in Paris at the significantly named Hotel Mars, and embarks on a whirlwind tour of the heavens, pushing further sun-ward than any astral traveler has gone before.

“We were floating close together in what seemed a sea of translucent light. I gazed upon countless solar systems, that like wheels within wheels revolved with such rapidity that they seemed all one wheel […] soaring through the radiance of the ring, which was like a sun woven into a circle, we soon left Saturn far behind us, and alighted on Venus. Here seas, mountains, forests, lakes, and meadows were one vast garden…”

Corelli’s book, like Flammarion’s, was somewhere between spiritualist tract and fiction; it included a postscript, “The Electric Principle of Christianity,” which is presented as true scripture. Other accounts were presented as simple fact. In 1899 a Geneva professor of psychology published a famous case study of the Swiss medium Hélène Smith’s visionary travels to Mars—complete with accounts of the Martian landscape and an elaborately invented Martian language. (Flournoy concluded, judiciously, that Smith was telekinetic, but was not actually having real visions of Mars). In New York, Sara Weiss, psychic, took dictation from the Martian spirit “Carl De L’Ester”:

Spirit: We are aware that in the minds of Earth’s thinkers there is a lively interest relating to a world of our Solar System, astronomically known as the Planet Mars. We, too, are greatly interested in the same direction, and it is our ardent desire that we may use you as a means through whom Earth’s peoples may obtain a closer acquaintance with the Planet. Medium: Since my early youth I have greatly desired to study astronomy, but always circumstances have prevented my gaining more than a very slight knowledge of this, to me, most wonderful of sciences; so, as in the undertaking some astronomical features are involved, without further hesitation I accept your proposal to attempt to make use of my organism for what I feel secured is a wise and benevolent purpose.

And of course these spiritualist tropes found their way into more standardly science-fictional writing. John Carter made his way to Mars by “meditating” on the “overpowering fascination” of Mars until “I closed my eyes, stretched out my arms … and felt myself drawn with the suddenness of thought through the trackless immensity of space.” Edwin Lester Arnold’s hero Gullivar Jones got to Mars by means of a straight-up magic carpet. Voyage To Arcturus begins with a séance. Wells’ Martians were telepathic. And so on.

So, anyway: after reading a great deal of this sort of thing, some of which is heavy going, honestly, I had enough for a book. The craze encompassed a range of clashing ideas, which I tried to assign to different voices in the book: spiritualist visions of a heavenly Mars (Flammarion’s Martians were ethereal, winged pacifist body-switching dead-raising matriarchal angels) clashed with materialist visions (Lowell imagined a dying world, a desert on which life could survive only through ruthlessly organized planetary irrigation) and with nightmares (Wells’ vision of Mars as a mirror of the horrors of colonialism)….

The book’s working title was A Planetary Romance, which was universally agreed to be awful. In the end I called it The Revolutions, as in of the heavenly spheres. It mostly takes place between 1893 and 1895-ish, within this odd little overheated historical bubble of enthusiasm; a moment when it looked like science and modernity might mean something very different from the way they look now (not to mention science fiction). It has a meeting between two respectable Victorians for the purpose of traveling to the planets, though neither of them ended up very much like Gardner or Horniman in other ways, and the society they belong to is not very much like the Golden Dawn. There are clairvoyants, and yes, there are Martians. There was a lot of strange stuff that I couldn’t fit in, and I am pleased to have got some of it out of my head and put it down here.

Felix Gilman was born in London and grew up in the south London suburbs. He attended school in Sevenoaks, Kent, and read history at Oxford for three years, then got a master’s degree in “Elizabethan stuff,” graduating in 1996. His latest novel, The Revolutions, is available now from Tor Books.