The Archetypes and the Collective Unconscious – C G Jung

The nixie is an even more instinctive version of a magical feminine being whom I call the anima. She can also be a siren, melusina (mermaid), wood-nymph, Grace, or Erlking's daughter, or a lamia or succubus, who infatuates young men and sucks the life out of them.

Moralizing critics will say that these figures are projections of soulful emotional states and are nothing but worthless fantasies. One must admit that there is a certain amount of truth in this. But is it the whole truth? Is the nixie really nothing but a product of moral laxity?

Were there not such beings long ago, in an age when dawning human consciousness was still wholly bound to nature? Surely there were spirits of forest, field, and stream long before the question of moral conscience ever existed. What is more, these beings were as much dreaded as adored, so that their rather peculiar erotic charms were only one of their characteristics.

Man's consciousness was then far simpler, and his possession of it absurdly small.  An unlimited amount of what we now feel to be an integral part of our psychic being disports itself merrily for the primitive in projections ranging far and wide.

The word "projection" is not really appropriate, for nothing has been cast out of the psyche; rather, the psyche has attained its present complexity by a series of acts of introjection. Its complexity has increased in proportion to the despiritualisation of nature.

 An alluring nixie from the dim bygone is today called an "erotic fantasy," and she may complicate our psychic life in a most painful way. She comes upon us just as a nixie might; she sits on top of us like a succubus; she changes into all sorts of shapes like a witch, and in general displays an unbearable independence that does not seem at all proper in a psychic content. Occasionally she causes states of fascination that rival the best bewitchment, or unleashes terrors in us not to be outdone by any manifestation of the devil. She is a mischievous being who crosses our path in numerous transformations and disguises, playing all kinds of tricks on us, causing happy and unhappy delusions, depressions and ecstasies, outbursts of affect, etc.

Even in a state of reasonable introjection the nixie has not laid aside her roguery. The witch has not ceased to mix her vile potions of love and death; her magic poison has been refined into intrigue and self-deception, unseen though none the less dangerous for that.