To Alice Raphael Eckstein
Dear Mrs. Eckstein, 16 September 1930
Thank you very much for your long and interesting letter.
It is surely a very interesting problem, the question of the relation between brain and consciousness.
Everyday experience tells us that consciousness and brain are in an indispensable connection.
Destruction of the latter results in an equal destruction of the former.
Bergson is quite right when he thinks of the possibility of a relatively loose connection between the brain and consciousness, because despite our ordinary experience the connection might be less tight than we suppose.
There is no reason why one shouldn’t suppose that consciousness could exist detached from a brain.
Thus far there is no difficulty for our assumption.
But the real difficulty begins when it comes to the actual showdown, namely when you should prove that there is consciousness without a brain.
It would amount to the hitherto unproven fact of an evidence that there are ghosts.
I think it is the most difficult thing in the world to produce evidence in that respect entirely satisfactory from a scientific point of view.
As a matter of fact, it is the hardest thing I could imagine.
I frankly confess I don’t know at all how such a proof would look.
How can one establish indisputable evidence for the existence of a consciousness without a brain?
I might be satisfied if such a consciousness would be able to write an intelligent book, invent new apparatuses, provide us with new information that couldn’t be possibly found in human brains, and if it were evident that there was no high-power medium among the spectators.
But such a thing is quite unthinkable.
I therefore consider the possibility of proving an incorporeal consciousness an extremely unlikely one.
Trance conditions are certainly very interesting and I know a good deal about them though never enough.
But they wouldn’t yield any strict evidence, because they are the conditions of a living brain.
Yes, I know of the Tarot.
It is, as far as I know, the pack of cards originally used by the Spanish gypsies, the oldest cards historically known.
They are still used· for divination purposes.
If ever you should have new experiences I shall be most interested to hear of them.
Very sincerely yours,
C.G. Jung ~Carl Jung, Letters Vol. 1, Pages 76-77