Recently I reread Carl Jung's Confrontation with the Unconscious (in his biography Memories, Dreams, Reflections). The contents of his inner search has now been published in his Red Book, a document that his heirs refused to publish due to its possible negative image upon Jung. His granddaughter finally came to the decision to publish and interested readers can now share Jung's personal experience, though the route itself has already been outlined in his biography which was published before his death in 1961.
Metaphorically speaking, Jung's route is his venture searching for angels and demons in his unconscious (personal as well as collective). The contents of which were actually an "one man's experience", but his act of search has contemporary relevance, in particular for those who are interested in deep meditation.
This is what Jung said in conceptualizing his search:
"I was frequently so wrought up that I had to do certain yoga exercises in order to hold my emotions in check. But since it was my purpose to know what was going on within myself, I would do these exercises only until I had calmed myself enough to resume my work with the unconscious. As soon as I had the feeling that I was myself again, I abandoned this restraint upon the emotions and allowed the images and inner voices to speak afresh. The Indian, on the other hand, does yoga exercises in order to obliterate completely the multitude of psychic contents and images."
A number of questions and answers:
Q1: Why did Jung need to practice yoga?
A1: He feared that if he didn't have enough conscious control, he might trigger a self-induced psychosis.
Q2: Did Taoist practitioners seek angels and demons?
A2: Similar to yoga practitioners, as mentioned by Jung, classical Taoist practitioners do not seek angels and demons. In particular, Masters warned practitioners not to treat such images as real and should instead treat them as fantasies when their appear. And the way for them to disappear is to increase and balance one's yang-chi (阳气).
An interesting question follows: is there still a valid reason seeking for angels and demons in one's meditative practice? How about for psychiatrists like Jung?
My answer is a definitely NO! The contemporary treatment of severe psychotic conditions, like schizophrenia, uses psychotic drugs, thanks to the progress of the pharmaceutical industry (instead of the highly unsure route of trying to dig into the patient's unconscious, and hopefully the patient can reconnect with his suppressed contents and thereby, hopefully again, to integrate his split-apart personality back to a whole that is under the control of his consciousness: the gist of psychoanalytical treatment ). And for minor conditions, like early psychosis (思覺失調， a medical term first used in Hong Kong), the treatment will generally be cognitive counseling, perhaps together with the administration of anti-depression drugs.
Generally speaking, it is not advisable for people with any psychotic tendency to practice deep meditation, lest part of one's unconscious will be split into a separate personality.
For the inquisitive meditators, we can speculate some might be tempted to get a peep at their own (or humanity's if collective unconscious is involved) darker side (no negative connotation intended). Before such plunge, one might perhaps read what Jung said on his own experience, and I rest my case with the following quotation:
"In order to grasp the fantasies which were stirring in me “underground,” I knew that I had to let myself plummet down into them, as it were. I felt not only violent resistance to this, but a distinct fear. For I was afraid of losing command of myself and becoming a prey to the fantasies — and as a psychiatrist I realized only too well what that meant. After prolonged hesitation, however, I saw that there was no other way out. I had to take the chance, had to try to gain power over them; for I realized that if I did not do so, I ran the risk of their gaining power over me. A cogent motive for my making the attempt was the conviction that I could not expect of my patients something I did not dare to do myself. The excuse that a helper stood at their side would not pass muster, for I was well aware that the so-called helper — that is, myself — could not help them unless he knows their fantasy material from his own direct experience, and that at present all he possessed were a few theoretical prejudices of dubious value. This idea — that I was committing myself to a dangerous enterprise not for myself alone, but also for the sake of my patients — helped me over several critical phases."