quotes from C. G. Jung: Psychology and Alchemy #1
[There is] in the dialectical discussion between the conscious mind and the unconscious, a development or an advance towards some goal or end, the perplexing nature of which has engaged my attention for many years. … It is a longissima via, not straight but snakelike, a path that unites the opposites in the manner of the guiding caduceus, a path whose labyrinthine twists and turns are not lacking in terrors.
The fountain of life as fons mercurialis.—Rosarium philosophorum (1550)