Paul Bishop (ed.), Jung in Contexts. 

As early as 1909, however, while starting work on ‘Transformations and Symbols of the Libido’, Jung had speculated in a letter to Freud of  April 1909 about the existence of ‘some quite special complex, a universal one having to do with the prospective tendencies in man’. From this speculation, Jung developed the notion of a psychology that did not just look back to the past but also looked forward to the future: ‘If there is a “psych[o]analysis” there must also be a “psychosynthesis” which creates future events according to the same laws.’16 Thus the logical distinction between analytic and synthetic judgments as set out by Kant in the first Critique became, for Jung, the conceptual basis of the distinction between what he saw as two entirely different psychologies. One of them—Freud’s—deals with the source of the neurosis (and hence, so Jung thought, says nothing new), whilst the other—Jung’s own—would deal with the trajectory of the neurosis and its implications for the future development of the patient (and hence, so Jung thought, would show what it meant). It remains unclear, however, why retrospective enquiry should be any less ‘synthetic’ than prospective enquiry. One might be forgiven for thinking that Jung merely presents the analogy between analytic/synthetic psychology and a concern with the past and with the future, rather than arguing for it. Yet the emphasis on ‘synthesis’ is intimately bound up with Jung’s redefinition of libido, and the goal of Jungian therapy. (4)