“Wonder after wonder was reported to have occurred in the spiritual circles and the lecture-rooms of the mesmerists; the sick were healed, the blind made to see, the lame to walk, the deaf to hear. J. R. Newton in America, and Du Potet in France, were healing the multitude without the slightest claim to divine intervention. The great discovery of Mesmer, which reveals to the earnest inquirer the mechanism of nature, mastered, as if by magical power, organic and inorganic bodies.
But this was not the worst. A more direful calamity for the Church occurred in the evocation from the upper and nether worlds of a multitude of “spirits”, whose private bearing and conversation gave the direct lie to the most cherished and profitable dogmas of the Church. These “spirits” claimed to be the identical entities, in a disembodied state, of fathers, mothers, sons, and daughters, friends and acquaintances of the persons viewing the weird phenomena.
The Devil seemed to have no objective existence, and this struck at the very foundation upon which the chair of St. Peter rested. Not a spirit except the mocking mannikins of Planchette would confess to the most distant relationship with the Satanic majesty, or accredit him with the governorship of a single inch of territory. The clergy felt their prestige growing weaker every day, as they saw the people impatiently shaking off, in the broad daylight of truth, the dark veils with which they had been blindfolded for so many centuries.
Then finally, fortune, which previously had been on their side in the long-waged conflict between theology and science, deserted to their adversary. The help of the latter to the study of the occult side of nature was truly precious and timely, and science has unwittingly widened the once narrow path of the phenomena into a broad highway. Had not this conflict culminated at the nick of time, we might have seen reproduced on a miniature scale the disgraceful scenes of the episodes of Salem witchcraft and the Nuns of Loudun. As it was, the clergy was muzzled.”
H. P. Blavatsky
The Mark Of God: Understanding Your "I AM Presence" 