Jason’s voyage to find the Golden Fleece can be interpreted by Jungians in the following way. Jason, the archetypal hero, must slay the dragon guarding the fleece; the dragon represents those dark impulses of his that he has to overcome if he is to attain the spiritual purity symbolized by the fleece. Unfortunately, Jason only defeats the dragon with a magic sleeping potion, leaving his dormant impulses undefeated.
[1]