20. According to the Spiritist doctrine, neither “angels” nor “devils” are beings apart from the rest of the creation; all the intelligent beings of the universe are of one and the same nature. United to material bodies, they constitute the human race which populates the Earth and other inhabited worlds of the universe; freed from those bodies, they constitute the spirit-world, or the spirits who people space. God has created them perfectible; God has given them an aim, viz., the attainment of perfection and of the happiness that is the consequence of perfection; but God has not given them perfection; God has willed that they should owe it to their own personal efforts, so that they might have all the merit of its acquisition. From the first moment of their creation, they progress incessantly, either in the state of incarnation or in the life of the spirit-world; once arrived at the culminating point of their purification they become pure spirits, or angels, according to the common expression; so that, from the embryo of the intelligent being to the angel, there is an uninterrupted chain, each link of which marks a degree in the scale of progress.
It follows, therefore, that there are spirits at every degree of moral and intellectual advancement, according as they are at the top, the bottom, or the middle, of the ladder; and that, consequently, there are, among them, spirits of every degree of knowledge and ignorance, of goodness and of badness. In the lower ranks of spirits there are some who are still deeply imbued with the love of evil and who take pleasure in doing wrong; spirits who may perfectly well be called demons, for they are capable of all the misdeeds attributed to the latter. If Spiritism abstains from giving them that name, it is because the world has attached to it the idea of beings distinct from the human race, of a nature essentially bad, doomed to evil for all eternity, and incapable of progressing in goodness.