From St. John of the Cross and Dr. C. J. Jung, Part III, Chapter 9. Inner Growth Books, 1986.

A Psychological Dark Night

Recollected people ply their bucket more assiduously than others, but since they are actually drawing up this water and expending it, the day arrives when the level of the water falls below the length of the rope that holds their bucket. This same phenomenon can be viewed from the point of view of the development of the various functions and attitudes in the process of individuation. The natural working of the faculties can then be understood as the use of the most conscious or superior function with its attendant attitude, aided by the auxiliary function. The conscious exercise of these functions, especially when it is deliberate and cultivated, can lead to the same dilemma of lack of conscious energy. What development that could have taken place through these functions has already been substantially achieved. There is no more psychic energy that can be attained through exercising them. What is needed is a new function through which to tap a deeper level of energy. Dr. Jung and his followers carefully fashioned various ways in which this new function, and thus new ways of proceeding, and new energy could be developed.

   For St. John, the most favorable prognosis for this diminishment of conscious energy would be the dawning of the experience of contemplation, and thus he gives the three signs for determining whether this is actually the case, but the three signs imply that there are other explanations possible, as we have just seen.