Jung's general ideas on therapy seem especially appropriate today in light of so many forms being available. Whether or not many are based on hit-or-miss assumption is unclear, as what is presented as deduction is often selectively pre-arranged to reiterate the premise. Aristotle introduced the idea of a "petitio principii" in 350 B. C.; but philosophical sophistries aside, there are other factors to be considered. Jung wrote in The Practice of Psychotherapy:

"Each of them rests on special psychological assumptions and produces special psychological results; comparison between them is difficult and often well-nigh impossible... Objective appraisal of the facts shows... that each of these methods is justified up to a point, since each can boast not only of certain successes but of psychological data that largely prove its particular assumption."

But, consciousness is a partial complex; relative to inner conditions. Without a concept of unconscious psychic functioning, processes outside it can only be seen as physiological. Hazy notions of "drives" and "reflexes" euphemize the instinctual psyche, and the projection of subjective ideas onto objective data results in logical contradictions:

"Thus we are faced... with a situation comparable with that in modern physics... where there are two contradictory theories of light... Contradictions in a department of science merely indicate that its subject can be grasped only by means of antinomies -- witness the wave theory and the corpuscular theory of light. Now the psyche is infinitely more complicated than light; hence a great number of antinomies are required to describe the nature of the psyche satisfactorily. One of the fundamental antinomies is... psyche depends on body and body depends on psyche. There are clear proofs for both sides of this antinomy, so that an objective judgment cannot give more weight to thesis or antithesis...

"The existence of valid contradictions shows that the object of investigation presents the inquiring mind with exceptional difficulties, as a result of which only relatively valid statements may be made... the statement is valid only in so far as it indicates what kind of psychic system we are investigating."

That two psychic systems co-exist in the human head should be apparent to anyone who's ever looked inside his own -- a mystery which is profoundly expressed in dreams. It's a vast and fluctuating continuum of body/mind that Jung showed to be scientifically uncertain territory; where the precision of the concept must replace direct measurement:

"Since the individuality of the psychic system is infinitely variable, there must be an infinite variety of relatively valid statements. But if individuality were absolute... if one individual were totally different from every other individual, then psychology would be impossible as a science, for it would consist in an insoluble chaos of subjective opinions. Individuality, however, is only relative, the complement of human conformity or likeness, and therefore it is possible to make statements of general validity, i. e., scientific statements. These statements relate only to those parts of the psychic system which do in fact conform, i. e., are amenable to comparison and statistically measurable; they do not relate to that part of the system which is individual and unique. The second fundamental antinomy in psychology therefore runs: the individual signifies nothing in comparison with the universal, and the universal signifies nothing in comparison with the individual."

Here lies the inconsistency in those methods founded on averages and statistics: where the individual coincides with the universal can't be assumed any more than where body becomes mind. How does therapy proceed from such logical contradictions?

"When, as a psychotherapist, I set myself up as a medical authority over my patient and on that account claim to know something about his individuality, or to be able to make valid statements about it, I am only demonstrating my lack of criticism, for I am in no position to judge the whole of the personality before me. I cannot say anything valid about him except in so far as he approximates to the "universal man." But since all life is to be found only in individual form, and I myself can assert of another individuality only what I find in my own, then I am in constant danger either of doing violence to the other person or of succumbing to his influence." 

Considering some therapies today, the danger is more for the patient than the therapist: "If I wish to treat another individual psychologically at all, I must for better or worse give up all pretensions to superior knowledge, all authority and desire to influence. I must perforce adopt a dialectical procedure consisting in a comparison of our mutual findings. But this becomes possible only if I give the other person a chance to play his hand to the full, unhampered by my assumptions. In this way his system is geared to mine and acts upon it; my reaction is the only thing with which I as an individual can legitimately confront my patient."

Freudians, Behaviorists, and Eye Rotation therapists may want to leave off here: "Any deviation from this attitude amounts to therapy by suggestion... Suggestion therapy includes all methods that arrogate to themselves, and apply, a knowledge or an interpretation of other individualities. Equally it includes all strictly technical methods, because these invariably assume that all individuals are alike. To the extent that the insignificance of the individual is a truth, suggestive methods, technical procedures, and theorems in any shape or form are entirely capable of success and guarantee results with the universal man -- as for instance, Christian Science, mental healing, faith cures, remedial training, medical and religious techniques, and countless other isms. Even political movements can, not without justice, claim to be psychotherapy in the grand manner."

Jung's method is a way of asking the questions we need to ask to arrive at a discourse with ourselves. Those who already have answers have no reason to ask questions. It's a symbolic process that begins with self-reflection.