Felix Culpa
The radicalness of Jung's position, though it has a long history within Christian tradition, involves what the Church calls a felix culpa, a fortunate fall. (3.55)
And it was the feminine principle, Gretel, who never gave up her faith in life, but continuously encouraged her despairing Hansel. When the right moment came, they were alert enough to throw their negativity in the fire and run. But that witch forced the development of their maturity and their recognition of what was of value to them (again, the felix culpa motif). (6.121)
The witch's act here may also be seen positively (a felix culpa) in that she is forcing the girl to wake up. The old life has to die to make way for the new. (5.96)