Jung - "Memories Dreams Reflections" pg. 223
gradually, through my scientific work, i was able to put my fantasies and the contents of the unconscious on a solid footing. words and paper, however, did not seem real enough to me; something more was needed. i had to achieve a kind of representation in stone of my innermost thoughts and of the knowledge i had acquired. Or, to put t another way, i had to make a confession of faith in stone. that was the beginning of the "Tower," the house which i built for myself at Bollingen.