The fusion of science, science fiction and the spiritual influenced other readers as well "With great commercial success he blended scientific speculation with science fiction to propagate modern myths such as the notion that “superior” extraterrestrial species reside on numerous planets, and that the human soul evolves through cosmic reincarnation. Among other things, he believed that all planets went through more or less the same stages of development, but at different rates depending on their sizes. Other than that, his writing about other worlds adhered fairly closely to then current ideas in evolutionary theory and astronomy. In "Lumen", a human character meets the soul of an alien, able to cross the universe faster than light, that has been reincarnated on many different worlds, each with their own gallery of organisms and their evolutionary history. His psychical studies also influenced some of his science fiction, where he would write about his beliefs in a cosmic version of metempsychosis. Man he considered to be a “citizen of the sky,” others worlds “studios of human work, schools where the expanding soul progressively learns and develops, assimilating gradually the knowledge to which its aspirations tend, approaching thus evermore the end of its destiny.” This belief in extraterrestrial life, Flammarion combined with a religious conviction derived, not from the Catholic faith upon which he had been raised, but from the writings of Jean Reynaud and their emphasis upon the transmigration of souls. In Real and Imaginary Worlds (1864) and Lumen (1887), he "describes a range of exotic species, including sentient plants which combine the processes of digestion and respiration. It is not quite clear if these two incidents are related to each other. In 1862 he published his first book, The Plurality of Inhabited Worlds, and was fired from his position at the Paris Observatory later the same year.
He was convinced that souls after the physical death pass from planet to planet, progressively improving at each new incarnation. He was influenced by Jean Reynaud (1806–1863) and his Terre et ciel (1854), which described a religious system based on the transmigration of souls believed to be reconcilable with both Christianity and pluralism.
He has been described as an "astronomer, mystic and storyteller" who was "obsessed by life after death, and on other worlds, and seemed to see no distinction between the two." In 1910, for the appearance of Halley's Comet, he believed the gas from the comet’s tail "would impregnate atmosphere and possibly snuff out all life on the planet." Īs a young man, Flammarion was exposed to two significant social movements in the western world: the thoughts and ideas of Darwin and Lamarck, and the rising popularity of spiritism with spiritualist churches and organizations appearing all over Europe. He also believed in 1907 that a seven-tailed comet was heading toward Earth. In 1907, he wrote that he believed that dwellers on Mars had tried to communicate with the Earth in the past. The " Flammarion engraving" first appeared in Flammarion’s 1888 edition of L’Atmosphère. The 1895 volume of the combined journal was numbered 9, to preserve the BSAF volume numbering, but this had the consequence that volumes 9 to 13 of L'Astronomie can each refer to two different publications, five years apart from each other. In January, 1895, after 13 volumes of L'Astronomie and 8 of BSAF, the two merged, making L’Astronomie the Bulletin of the Societé. He was a founder and the first president of the Société astronomique de France, which originally had its own independent journal, BSAF ( Bulletin de la Société astronomique de France), first published in 1887. He was the brother of Ernest Flammarion (1846–1936), founder of the Groupe Flammarion publishing house. Camille Flammarion was born in Montigny-le-Roi, Haute-Marne, France.