Along the same lines, the Indian mystic Sri Aurobindo wrote in a letter (I don't know the date of it, but it was obviously before 1950):
What do you mean by a ghost? The word “ghost” as used in popular parlance covers an enormous number of distinct phenomena which have no necessary connection with each other. To name a few only:
1. An actual contact with the soul of a human being in its subtle body and transcribed to our mind by the appearance of an image or the hearing of a voice.
2. A mental formation stamped by the thoughts and feelings of a departed human being on the atmosphere of a place or locality, wandering about there or repeating itself, till that formation either exhausts itself or is dissolved by one means or another. This is the explanation of such phenomena as the haunted house in which the scenes attending or surrounding or preceding a murder are repeated over and over again and many other similar phenomena.
3. A being of the lower vital planes who has assumed the discarded vital sheath of a departed human being or a fragment of his vital personality and appears and acts in the form and perhaps with the surface thoughts and memories of that person.
4. A being of the lower vital plane who by the medium of a living human being or by some other means or agency is able to materialise itself sufficiently so as to appear and act in a visible form or speak with an audible voice or, without so appearing, to move about material things, e.g., furniture or to materialise objects or to shift them from place to place. This accounts for what are called poltergeists, phenomena of stone-throwing, tree-inhabiting Bhutas, and other well-known phenomena.
5. Apparitions which are the formations of one’s own mind and take to the senses an objective appearance.
6. Temporary possession of people by vital beings who sometimes pretend to be departed relatives etc.
7. Thought-images of themselves projected, often by people at the moment of death, which appear at that time or a few hours afterwards to their friends or relatives.
Along the same lines, the Indian mystic Sri Aurobindo wrote in a letter (I don't know the date of it, but it was obviously before 1950):
What do you mean by a ghost? The word “ghost” as used in popular parlance covers an enormous number of distinct phenomena which have no necessary connection with each other. To name a few only:
1. An actual contact with the soul of a human being in its subtle body and transcribed to our mind by the appearance of an image or the hearing of a voice.
2. A mental formation stamped by the thoughts and feelings of a departed human being on the atmosphere of a place or locality, wandering about there or repeating itself, till that formation either exhausts itself or is dissolved by one means or another. This is the explanation of such phenomena as the haunted house in which the scenes attending or surrounding or preceding a murder are repeated over and over again and many other similar phenomena.
3. A being of the lower vital planes who has assumed the discarded vital sheath of a departed human being or a fragment of his vital personality and appears and acts in the form and perhaps with the surface thoughts and memories of that person.
4. A being of the lower vital plane who by the medium of a living human being or by some other means or agency is able to materialise itself sufficiently so as to appear and act in a visible form or speak with an audible voice or, without so appearing, to move about material things, e.g., furniture or to materialise objects or to shift them from place to place. This accounts for what are called poltergeists, phenomena of stone-throwing, tree-inhabiting Bhutas, and other well-known phenomena.
5. Apparitions which are the formations of one’s own mind and take to the senses an objective appearance.
6. Temporary possession of people by vital beings who sometimes pretend to be departed relatives etc.
7. Thought-images of themselves projected, often by people at the moment of death, which appear at that time or a few hours afterwards to their friends or relatives.