As J. G. Kiernan shows,[12] this doctrine, early in the history of the race, obtained dominance through the evolution of arts, sciences, and religions from fetichism. Phenomena manifested by fetich priests (of the Shaman type) so closely resembled epileptic insanity in its frenzies and visions that the two states were long regarded as identical, whence the term "_morbus sacer_." The supernatural influences which, in current belief, underlay epilepsy were, at the outset, malign or benign as they were offended or placated. They became benign, and the insane were under protection of a deity, as in Mussulman countries. Later still the demon-possession theory gained dominance, and at length the demon sank into disease. Throughout all this evolution the belief in an inherent affinity between insanity and genius persisted. Aristotle, in whose day the disease notion was becoming dominant, asserts that, under the influence of head congestion, persons sometimes become prophets, sybils, and poets. Thus Mark, the Syracusan, was a pretty fair poet during a maniacal attack, but could not compose when sane. Men illustrious in poetry, arts, and statesmanship are often insane, like Ajax, or misanthropic like Bellerophon. Even at a recent period similar dispositions are evident in Plato, Socrates, Empedocles, and many others, above all, the poets. According to Plato, "Delirium is by no means evil, but when it comes by gift of the gods, a very great benefit. In delirium the sibyls of Delphi and Dodona were of great service to Greece, but when in cold blood were of little or none. Frequently, when the gods afflicted men with epidemics, a sacred delirium inspired some men with a remedy for these. The Muses excite some souls to delirium to glorify heroes with poetry, or to instruct future generations." Precedent to the works of Morel and Moreau appeared their source and inspiration, Prosper Lucas's _Natural Heredity_.[13] Here the biologic current of thought encountered the sociologic current; although the waves clashed, the two currents merged into and modified each other. The biologist demonstrated that degenerate types often "threw back" in their structures, and this very "throwing back" made them the fittest to survive. The sociologist found that the only test of acquired or inherited degeneracy in man was disaccord with environment. The co-existent moral and physical defects resultant on heredity found by Erasmus Darwin, Rush, Parkman, Grohmann, and others tended to show that all types of defectives might be a product of heredity.