I believe there was a further reason that the later Jung invoked the Kantian framework so often when he discussed archetypes. If I can try to sum up a complex situation briefly, it would seem that Jung unwittingly conflated the issue of archetypal multivalence with the issue of whether archetypes could be directly knowable. On the one hand, Jung recognized and often stressed the fact that archetypes are always observed and experienced in a diverse multiplicity of possible concrete embodiments, so that the full essence and meaning of the archetype must be regarded as fundamentally transcending its many particular manifestations. On the other hand, however, he often conflated this crucial insight with the quite separate epistemological issue of whether archetypes can be directly experienced and known as principles that transcend the human psyche, or whether they can only be indirectly inferred by observing the configurations of psychological phenomena which are structured by archetypes that are ultimately unknowable in themselves (noumena). In his understandable attempt to preserve the multivalent indeterminacy of archetypes, transcending every particular embodiment, Jung called upon a Kantian framework of phenomenon and noumenon which seemed to entail the unknowability of the archetypes in themselves, their humanly unreachable essence beyond every diverse manifestation.
Jung seems not to have fully grasped the epistemological and ontological possibility of a genuine direct participation (in both the Platonic sense and the contemporary sense of co-creative enaction) in a dynamically multivalent archetype that in some sense remains indeterminate until concretely enacted. This theoretical limitation also informed and, I believe, helped produce Jung's many contradictory and confusing statements about the unconscious and the psyche, and about various metaphysical and spiritual issues such as God and the God-image, that fueled his famous controversies with Martin Buber and Fr. Victor White.
Jung's occasional unclarity about the nature of archetypes seems also to have been increased by his unconscious conflation of two different Kantian ideas in his discussions of archetypes. Jung saw archetypes, on the one hand, as a priori forms and categories, and on the other hand, as unknowable transcendent noumena which exist behind and beyond all phenomena (a point made by de Voogd, op. cit.). Thus for Jung, archetypes were essentially fulfilling both functions in the Kantian framework ”categories of experience and noumenal things-in-themselves ”but he did not seem aware that he moved back and forth between these two separate functions in his various statements and formulations.
Doubtless part of the confusion underlying Jung's many discussions of archetypes reflects the extremely complex and enigmatic problem of projection ”namely, how constellated archetypes can configure our lived reality and give meaning to our experience not only by shaping and constituting our perceptions but also, at times, by deeply distorting them. This issue is connected with another, equally complex and enigmatic. For in the background of Jung's conflicting philosophical loyalties and statements loomed his lifelong struggle with the disenchanted modern cosmos, which he both took seriously and saw through, and which had similarly shaped and confused Kant's philosophical struggles and formulations. Against the overwhelming contemporary scientific consensus concerning the disenchanted nature of the cosmos and the workings of nature, Jung could never be quite sure how much trust he should place in his spiritually revelatory observations and intuitions concerning a world embedded with purpose and meaning, despite the fact that the data repeatedly seemed to break out of a subjectivist or psychologistic confinement. So he hedged his bets by frequent allusions to Kant's philosophical strictures.
Since Jung's death, the extraordinary expansion of astrological research and evidence (compared with the more limited astrological data Jung was working with in his own lifetime), combined with a deeper philosophical and psychological understanding of the complex ontology and epistemology of archetypes, has helped to clarify the challenging issues with which he was increasingly confronted with each passing decade of his life and work. These issues have important philosophical implications beyond the fields of psychology and astrology. I believe that many of the major points of conflict and ambiguity within the postmodern mind concerning the social construction of knowledge, projection, subjectivism, relativism, pluralism, and participation will be helpfully illuminated by these developments in the archetypal astrological field.
An especially valuable resource for engaging some of these fundamental issues in postmodern thought outside the Jungian and astrological contexts, particularly as they concern the philosophy and psychology of religion, is Jorge Ferrer's Revisioning Transpersonal Theory: A Participatory Vision of Human Spirituality (Albany, New York: State University of New York Press, 2002).