The Spirits' Book
Book Two - The Spirit World
Chapter IX - Intervention of Spirits on the Physical World
482. How can the abnormal state of convulsionaries and hysterical individuals suddenly strike an entire population?
“Out of sympathy. Moral dispositions are communicated quite easily in certain cases. Surely you are not so unaware of the effects of human magnetism that you are unable to understand this. There is also the natural role of certain spirits in such occurrences, through sympathy with those by whom they are produced.”
Somnambulism and magnetism show us numerous examples of bizarre behavior identical to the ones convulsionaries display. These include physical insensitivity, thought reading, sympathetic transmission of pain, and so on. This makes it impossible to doubt that these hysterical individuals are experiencing some sort of waking somnambulism, determined by the influence that they inadvertently exercise upon each other. At the same time, they are both magnetizers and magnetized without even realizing it.