To James Kirsch
Dear Kirsch, 5 March 1954
The integration of the collective unconscious amounts roughly to taking cognizance of the world and adapting to it.
This does not mean that one would have to learn to know the whole world, or that one must have lived in all climates and continents of the world.
The integration of the unconscious is always, of course, only a very relative affair, and refers only to the constellated material, not to its total theoretical scope.
John of the Cross's "Dark Night of the Soul" has nothing to do with this.
Rather, integration is a conscious confrontation, a dialectical process such as I have described in my essay "The Relations between the Ego and the Unconscious."
A great deal of fog seems to have spread itself over this point.
With best regards,
Yours very sincerely,
C.G. Jung ~Carl Jung, Letters Vol. II, Page 159.