The role of fantasy in our psyche is a fascinating one. It acts as a driver of unconscious energy. Its role in spirituality is equally intriguing which Jung explores in his volume on Psychological Types:
By fantasy I understand two different things: 1. a fantasm, and 2. imaginative activity. In the present work the context always shows which of these meanings is intended. By fantasy in the sense of fantasm I mean a complex of ideas that is distinguished from other such complexes by the fact that it has no objective referent. Although it may originally be based on memory-images of actual experiences, its content refers to no external reality; it is merely the output of creative psychic activity, a manifestation or product of a combination of energized psychic elements. In so far as psychic energy can be voluntarily directed, a fantasy can be consciously and intentionally produced, either as a whole or at least in part. In the former case it is nothing but a combination of conscious elements, an artificial experiment of purely theoretical interest. In actual everyday psychological experience, fantasy is either set in motion by an intuitive attitude of expectation, or it is an irruption of unconscious contents into consciousness.
 We can distinguish between active and passive fantasy. Active fantasies are the product of intuition (q.v.), i.e., they are evoked by an attitude (q.v.) directed to the perception of unconscious contents, as a result of which the libido (q.v.) immediately invests all the elements emerging from the unconscious and, by association with parallel material, brings them into clear focus in visual form. Passive fantasies appear in visual form at the outset, neither preceded nor accompanied by intuitive expectation, the attitude of the subject being wholly passive. Such fantasies belong to the category of psychic automatisms. Naturally, they can appear only as a result of a relative dissociation of the psyche, since they presuppose a withdrawal of energy from conscious control and a corresponding activation of unconscious material. Thus the vision of St. Paul43 presupposes that unconsciously he was already a Christian, though this fact had escaped his conscious insight.
 It is probable that passive fantasies always have their origin in an unconscious process that is antithetical to consciousness, but invested with approximately the same amount of energy as the conscious attitude, and therefore capable of breaking through the latter’s resistance. Active fantasies, on the other hand, owe their existence not so much to this unconscious process as to a conscious propensity to assimilate hints or fragments of lightly-toned unconscious complexes and, by associating them with parallel elements, to elaborate them in clearly visual form. It is not necessarily a question of a dissociated psychic state, but rather of a positive participation of consciousness.
 Whereas passive fantasy not infrequently bears a morbid stamp or at least shows some trace of abnormality, active fantasy is one of the highest forms of psychic activity. For here the conscious and the unconscious personality of the subject flow together into a common product in which both are united. Such a fantasy can be the highest expression of the unity of a man’s individuality (q.v.), and it may even create that individuality by giving perfect expression to its unity. As a general rule, passive fantasy is never the expression of a unified individuality since, as already observed, it presupposes a considerable degree of dissociation based in turn on a marked conscious/unconscious opposition. Hence the fantasy that irrupts into consciousness from such a state can never be the perfect expression of a unified individuality, but will represent mainly the standpoint of the unconscious personality. The life of St. Paul affords a good example of this: his conversion to Christianity (see below) signified an acceptance of the hitherto unconscious standpoint and a repression of the hitherto anti-Christian one, which then made itself felt in his hysterical attacks. Passive fantasy, therefore, is always in need of conscious criticism, lest it merely reinforce the standpoint of the unconscious opposite. Whereas active fantasy, as the product of a conscious attitude not opposed to the unconscious, and of unconscious processes not opposed but merely compensatory to consciousness, does not require criticism so much as understanding.
 In fantasies as in dreams (which are nothing but passive fantasies), a manifest and a latent meaning must be distinguished. The manifest meaning is found in the actual “look” of the fantasy image, in the direct statement made by the underlying complex of ideas. Frequently, however, the manifest meaning hardly deserves its name, although it is always far more developed in fantasies than in dreams, probably because the dream-fantasy usually requires very little energy to overcome the feeble resistance of the sleeping consciousness, with the result that tendencies which are only slightly antagonistic and slightly compensatory can also reach the threshold of perception. Waking fantasy, on the other hand, must muster considerable energy to overcome the inhibition imposed by the conscious attitude. For this to take place, the unconscious opposite must be a very important one in order to break through into consciousness. If it consisted merely of vague, elusive hints it would never be able to direct attention (conscious libido) to itself so effectively as to interrupt the continuity of the conscious contents. The unconscious opposite, therefore, has to depend on a very strong inner cohesion, and this expresses itself in an emphatic manifest meaning.
 The manifest meaning always has the character of a visual and concrete process which, because of its objective unreality, can never satisfy the conscious demand for understanding. Hence another meaning of the fantasy, in other words its interpretation or latent meaning, has to be sought. Although the existence of a latent meaning is by no means certain, and although the very possibility of it may be contested, the demand for understanding is a sufficient motive for a thorough-going investigation. This investigation of the latent meaning may be purely causal, inquiring into the psychological origins of the fantasy. It leads on the one hand to the remoter causes of the fantasy in the distant past, and on the other to ferreting out the instinctual forces which, from the energic standpoint, must be responsible for the fantasy activity. As we know, Freud has made intensive use of this method. It is a method of interpretation which I call reductive (q.v.). The justification of a reductive view is immediately apparent, and it is equally obvious that this method of interpreting psychological facts suffices for people of a certain temperament, so that no demand for a deeper understanding is made. If somebody shouts for help, this is sufficiently and satisfactorily explained when it is shown that the man is in immediate danger of his life. If a man dreams of a sumptuous feast, and it is shown that he went to bed hungry, this is a sufficient explanation of his dream. Or if a man who represses his sexuality has sexual fantasies like a medieval hermit, this is satisfactorily explained by a reduction to sexual repression.
 But if we were to explain Peter’s vision (see below) by reducing it to the fact that, being “very hungry,” he had received an invitation from the unconscious to eat animals that were “unclean,” or that the eating of unclean beasts merely signified the fulfilment of a forbidden wish, such an explanation would send us away empty. It would be equally unsatisfactory to reduce Paul’s vision to his repressed envy of the role Christ played among his fellow countrymen, which prompted him to identify himself with Christ. Both explanations may contain some glimmering of truth, but they are in no way related to the real psychology of the two apostles, conditioned as this was by the times they lived in. The explanation is too facile. One cannot discuss historical events as though they were problems of physiology or a purely personal chronique scandaleuse. That would be altogether too limited a point of view. We are therefore compelled to broaden very considerably our conception of the latent meaning of fantasy, first of all in its causal aspect. The psychology of an individual can never be exhaustively explained from himself alone: a clear recognition is needed of the way it is also conditioned by historical and environmental circumstances. His individual psychology is not merely a physiological, biological, or moral problem, it is also a contemporary problem. Again, no psychological fact can ever be exhaustively explained in terms of causality alone; as a living phenomenon, it is always indissolubly bound up with the continuity of the vital process, so that it is not only something evolved but also continually evolving and creative.
 Anything psychic is Janus-faced—it looks both backwards and forwards. Because it is evolving, it is also preparing the future. Were this not so, intentions, aims, plans, calculations, predictions and premonitions would be psychological impossibilities. If, when a man expresses an opinion, we simply relate it to an opinion previously expressed by someone else, this explanation is quite futile, for we wish to know not merely what prompted him to do so, but what he means by it, what his aims and intentions are, and what he hopes to achieve. And when we know that, we are usually satisfied. In everyday life we instinctively, without thinking, introduce a final standpoint into an explanation; indeed, very often we take the final standpoint as the decisive one and completely disregard the strictly causal factor, instinctively recognizing the creative element in everything psychic. If we do this in everyday life, then a scientific psychology must take this fact into account, and not rely exclusively on the strictly causal standpoint originally taken over from natural science, for it has also to consider the purposive nature of the psyche.
 If, then, everyday experience establishes beyond doubt the final orientation of conscious contents, we have absolutely no grounds for assuming, in the absence of experience to the contrary, that this is not the case with the contents of the unconscious. My experience gives me no reason at all to dispute this; on the contrary, cases where the introduction of the final standpoint alone provides a satisfactory explanation are in the majority. If we now look at Paul’s vision again, but this time from the angle of his future mission, and come to the conclusion that Paul, though consciously a persecutor of Christians, had unconsciously adopted the Christian standpoint, and that he was finally brought to avow it by an irruption of the unconscious, because his unconscious personality was constantly striving toward this goal—this seems to me a more adequate explanation of the real significance of the event than a reduction to personal motives, even though these doubtless played their part in some form or other, since the “all-too-human” is never lacking. Similarly, the clear indication given in Acts 10:28 of a purposive interpretation of Peter’s vision is far more satisfying than a merely physiological and personal conjecture.
 To sum up, we might say that a fantasy needs to be understood both causally and purposively. Causally interpreted, it seems like a symptom of a physiological or personal state, the outcome of antecedent events. Purposively interpreted, it seems like a symbol, seeking to characterize a definite goal with the help of the material at hand, or trace out a line of future psychological development. Because active fantasy is the chief mark of the artistic mentality, the artist is not just a reproducer of appearances but a creator and educator, for his works have the value of symbols that adumbrate lines of future development. Whether the symbols will have a limited or a general social validity depends on the viability of the creative individual. The more abnormal, i.e., the less viable he is, the more limited will be the social validity of the symbols he produces, though their value may be absolute for the individual himself.
 This brings us to the second connotation of fantasy, namely imaginative activity. Imagination is the reproductive or creative activity of the mind in general. It is not a special faculty, since it can come into play in all the basic forms of psychic activity, whether thinking, feeling, sensation, or intuition (qq.v.). Fantasy as imaginative activity is, in my view, simply the direct expression of psychic life,45 of psychic energy which cannot appear in consciousness except in the form of images or contents, just as physical energy cannot manifest itself except as a definite physical state stimulating the sense organs in physical ways. For as every physical state, from the energic standpoint, is a dynamic system, so from the same standpoint a psychic content is a dynamic system manifesting itself in consciousness. We could therefore say that fantasy in the sense of a fantasm is a definite sum of libido that cannot appear in consciousness in any other way than in the form of an image. A fantasm is an idée-force. Fantasy as imaginative activity is identical with the flow of psychic energy.
I have reproduced the stories of Paul and Peter that Jung refers to below.
Acts 10:9-16 Peter’s Vision
About noon the following day as they were on their journey and approaching the city, Peter went up on the roof to pray. He became hungry and wanted something to eat, and while the meal was being prepared, he fell into a trance. He saw heaven opened and something like a large sheet being let down to earth by its four corners. It contained all kinds of four-footed animals, as well as reptiles of the earth and birds of the air. Then a voice told him, “Get up, Peter. Kill and eat.”
“Surely not, Lord!” Peter replied. “I have never eaten anything impure or unclean.”
The voice spoke to him a second time, “Do not call anything impure that God has made clean.”
This happened three times, and immediately the sheet was taken back to heaven.
Acts 9:1-9 Paul’s conversion
Meanwhile, Saul was still breathing out murderous threats against the Lord’s disciples. He went to the high priest and asked him for letters to the synagogues in Damascus, so that if he found any there who belonged to the Way, whether men or women, he might take them as prisoners to Jerusalem. As he neared Damascus on his journey, suddenly a light from heaven flashed around him. He fell to the ground and heard a voice say to him, “Saul, Saul, why do you persecute me?”
“Who are you, Lord?” Saul asked. “I am Jesus, whom you are persecuting,” he replied.
“Now get up and go into the city, and you will be told what you must do.”
The men traveling with Saul stood there speechless; they heard the sound but did not see anyone.
Saul got up from the ground, but when he opened his eyes he could see nothing. So they led him by the hand into Damascus. For three days he was blind, and did not eat or drink anything.