From 'Memories, Dreams, Reflections' (1954):
"Freud was able to interpret the dreams I was then [on their trip to
the USA in 1909] having only incompletely or not at all. They were
dreams with collective contents, containing, a great deal of symbolic
material. One in particular was important to me, for it led me for the
first time to the concept of the 'collective unconscious'... ."
"This was the dream. I was in a house I did not know, which had two
stories. It was 'my house.' I found myself in the upper story, where
there was a kind of salon furnished with fine old pieces in rococo
style. On the walls hung a number of precious old paintings. I wondered
that this should be my house, and thought, 'Not bad.' But then it
occtured to me that I did not know what the lower floor looked like.
Descending the stairs, I reached the ground floor. There everything was
much older, and I realized that this part of the house must date from
about the fifteenth or sixteenth century. The furnishings were medieval;
the floors were of red brick. Everywhere it was rather dark. I went
from one room to another, thinking, 'Now I really must explore the whole
house.' I came upon a heavy door, and opened it. Beyond it, I
discovered a stone stairway that led down into the cellar. Descending
again, I found myself in a beautifully vaulted room which looked
exceedingly ancient. Examining the walls, I discovered layers of brick
among the ordinary stone blocks, and chips of brick in the mortar. As
soon as I saw this I knew that the walls dated from Roman times. My
interest by now was intense. I looked more closely at the floor. It was
of stone slabs, and in one of these I discovered a ring. When I pulled
it, the stone slab lifted, and again I saw a stairway of narrow stone
steps leading down into the depths. These, too, I descended, and entered
a low cave cut into the rock. Thick dust lay on the floor, and in the
dust were scattered bones and broken pottery, like remains of a
primitive culture. I discovered two human skulls, obviously very old and
half disintegrated. Then I awoke."
"I saw from this that he was completely helpless in dealing with
certain kinds of dreams and had to take refuge in his doctrine. I
realized that it was up to me to find out the real meaning of the dream.
It was plain to me that the house represented a kind of image of the
psyche--that is to say, of my then state of consciousness, with hitherto
unconscious additions. Consciousness was represented by the salon. It
had an inhabited atmosphere, in spite of its antiquated style.
The ground floor stood for the first level of the unconscious. The
deeper I went, the more alien and the darker the scene came. In the
cave, I discovered remains of a primitive culture, that is, the world of
the primitive man within myself--a world which can scarcely be reached
or illuminated by consciousness. The primitive psyche of man borders on
the life of the animal soul, just as the caves of prehistoric times were
usually inhabit by animals before men laid claim to them.
During this period I became aware of how keenly I felt the difference
between Freud's intellectual attitude and mine. I had grown up in the
intensely historical atmosphere of Basel at the end of the nineteenth
century, and had acquired, thanks to reading the old philosophers, some
knowledge of the history of Psychology. When I thought about dreams and
the contents of the unconscious, I never did so without making
historical comparisons;... . I was especially familiar with the writers
of the eighteenth and early nineteenth century. Theirs was the world
which had formed the atmosphere of my first-story salon. By contrast, I
had the impression that Freud's intellectual history began with Buchner,
Moleschott, Du Bois-Reymond, and Darwin."
"The dream pointed out that there were further reaches to the state
of consciousness... : the long uninhabited ground floor in medieval
style, then the Roman cellar, and finally the prehistoric cave. These
signified past times and passed stages of consciousness.
Certain questions had been much on my mind during the days preceding
this dream. They were: On what premises is Freudian psychology founded?
[...] What is the relationship of its almost exclusive personalism to
general historical assumptions? My dream was giving me the answer. It
obviously pointed to the foundations of cultural history--a history of
successive layers of consciousness. My dream thus constituted a kind of
structural diagram of the human psyche; it postulated something of an
altogether impersonal nature underlying that psyche. It 'clicked,' as
the English have it--and the dream became for me a guiding image... .
This was my first inkling of a collective a priori beneath the personal psyche."
"The dream of the house had a curious effect upon me: it revived my
old interest in archaeology. After I had returned to Zurich I took up a
book on Babylonian excavations, and read various works on myths."
[Jung also describes this vision in his 'Mind and Earth' (1931):
"Perhaps I may be allowed a comparison: it is as though we had to
describe and explain a building whose upper storey was erected in the
nineteenth century, the ground floor dates back to the sixteenth
century, and careful examination of the masonary reveals that it was
reconstructed from a tower built in the eleventh century. In the cellar
we come upon Roman foundations, and under the cellar a choked-up cave
with neo-lithic tools in the upper layer and remnants of fauna from the
same period inthe lower layers. That would be the picture of our
psychic structure. We live on the upper storey and are only aware that
the lower storey is slightly old-fashioned. As to what lies beneath the
earth's surface, of that we remain totally unconscious.
This is a lame analogy.. for in the psyche there is nothing that is
just a dead relic. Everything is alive, and our upper story,
consciousness, is continually influenced by its living and active
foundations. Like the building, it is sustained and supported by
them."]
"Before I discovered alchemy, I had a series of dreams which
repeatedly dealt with the same theme. Beside my house stood another,
that is to say, another wing or annex, which was strange to me. Each
time I would wonder in my dream why I did not know this house, although
it had apparently always been there. Finally came a dream in which I
reached the other wing. I discovered there a wonderful library, dating
largely from the sixteenth and seventeenth centuries. Large, fat folio
volumes, bound in pigskin, stood along the walls. Among them were a
number of books embellished with copper engravings of a strange
character, and illustrations containing curious symbols such as I had
never seen before. At the time I did not know to what they referred;
only much later did I recognize them as alchemical symbols. In the dream
I was conscious only of the fascination exerted by them and by the
entire library. It was a collection of medieval incunabula and sixteenth
century prints.
The unknown wing of the house was... an aspect of myself; it
represented something that belonged to me but of which I was not yet
conscious. It, and especially the library, referred to alchemy, of which
I was ignorant, but which I was soon to study. Some fifteen years later
I had assembled a library very like the one in the dream."
"The late alchemical texts are fantastic and baroque; only after we
have learned how to interpret them can we recognize what treasures they
hide."
"Occasionally I would look at the pictures, and each time I would
think, 'Good Lord, what nonsense! This stuff is impossible to
understand.' [...] Finally I realized that the alchemists were talking
in symbols- those old acquaintances of mine. 'Why, this is fantastic,' I
thought. 'I simply must learn to decipher all this.'"
"I therefore decided to start a lexicon of key phrases with cross
references. [...] I worked along philological lines, as if I were trying
to solve the riddle of an unknown language."
"I had very soon seen that analytical psychology coincided in a most
curious way with alchemy. The experiences of the alchemists were, in a
sense, my experiences, and their world was my world. This was, of
course, a momentous discovery: I had stumbled upon the historical
counterpart of my psychology of the unconscious. The possibility of a
comparison with alchemy, and the uninterrupted intellectual chain back
to Gnosticism, gave substance to my psychology. When I pored over these
old texts everything fell into place: the fantasy-images, the empirical
material I had gathered in my practice, and the conclusions I had drawn
from it. I now began to understand what these psychic contents meant
when seen in historical perspective. My understanding of their typical
character, which had already begun with my investigation of myths, was
deepened. The primordial images and the nature of the archetype took a
central place in my researches, and it became clear to me that without
history there can be no psychology, and certainly no psychology of the
unconscious."