transmigration of souls
Transmigration of souls is a theological doctrine, also known as metempsychosis or palingenesis, which became popular during the Enlightenment as the scale of the Universe, and the vast number of planets that might exist, began to become clear. It taught that the soul, after death, would inhabit a succession of other worlds, becoming progressively more perfect. As Karl Guthe wrote:1
Such a concept of perfectibility linked to migration between planets offers a perspective in which the fears of inferiority, or isolation, or of being lost in a cosmos are transformed into ultimate triumph for the immortal part of man's being.
It was embraced in various forms by, among others, Thomas Wright, Charles Bonnet, Immanuel Kant, Humphry Davy, Jean Reynaud, and Camille Flammarion. The vast public readership of Flammarion's writings, in particular, ensured that belief in transmigration remained in circulation until the beginning of the twentieth century.
1. Guthe, Karl S. The Last Frontier: Imagining Other Worlds from the Copernican Revolution to Modern Science Fiction. Ithaca, N.Y.: Cornell University Press (1990).