Imaginatio is the active evocation of (inner) images secundum naturam, an authentic feat of thought or ideation, which does not spin aimless and groundless fantasies ‘into the blue’
Jung defines imaginatio as the disciplined, nature-guided power of inner image-creation, rigorously distinguished from arbitrary fantasy, establishing the conceptual foundation for all subsequent depth-psychological uses of the term.
, Psychology and Alchemy, 1944thesis