MEDIUMSHIP: SPEAKING AND WRITING MEDIUMS 

SPEAKING MEDIUMS: 
Definition | Frequent Use in Sessions | Conscious & Unconscious Psychophony
WRITING MEDIUMS: 
Definition | Conscious & Unconscious Psychography | Long Training | The Signature
Additional Considerations

Writing Mediums

Definition

The faculty exercised by writing mediums, also called psychography, is that which permits a spirit to act upon and utilize the arm and hand of the incarnate medium to transmit its message through writing.   Sometimes, the mediums hand and arm may be used in some kind of gesture such as becoming agitated convulsively or striking the table angrily, though as Kardec notes, this always denotes the presence of imperfect spirits. 

Like the process that takes place in psychophony, in order for this to happen, the medium enters into a mediumistic trance that allows the bonds between his spirit and his material body to loosen, whereby his spirit temporarily disengages from the physical body¹, thereby "loaning", so to speak, his body¹ to the communicating spirit.

¹ though only partially, i.e. always remains connected via a fluidic "chord", since complete separation would mean death.