Allan Kardec. The book of spirits (№ 396908)

Question: What is the effect of verbal formulas and techniques by which some people claim to subjugate the will of the spirits?
Answer: their Effect is such that people really believe in all this will be funny; otherwise, it will simply crooks, deserving of punishment. All sorts of verbal formulas is not more than buffoonery; no sacramental words, any cabalistic sign, no talisman, which would have any effect on the spirits, because spirits are involved only the thought, not the material things.