"How to Speak with the Dead" is one of the better guides to mediumship and the conducting of the then-modern seance ever written. Speaking of telepathy and the general philosophy of what a spirit is constituted of, it carefully straddles rationalism and spiritualism. This occult work is one part how-to guide to communicating with the spirits of the dead, one part philosophical tract, and one part view to theory and practice that was then hotly debated, trying to clear up what Sciens feels are misconceptions held by mystics of his age.