The discussion about incest is really then at what level incest is appropriate, if any. The outer form of incest is inarguably destructive and pathological but can the same be said about the inner form of incest?
In his paper “The Incest Taboo and the Virgin Archetype“, John Laylard argues that the incest taboo had to be introduced for a two-fold purpose.
The manifest purpose of the incest taboo was the expansion of society. When marrying one’s sibling became unacceptable, cousin marriage was introduced which favored a state of mutual cooperation among historically larger and larger kinship systems. The obligation to search for a wife or a husband further than one’s blood relatives thus became an imperative towards more peace—or at least less hostility—towards foreigners.
Second, the latent purpose is what Laylard calls “the realization of the anima within”. The prohibition of incest forced the incestuous desire into an external search beyond the primacy of the mother or the sister. This unfulfilled longing was then projected onto the first cousin or second cousin. In larger kinship systems such as the one we are living in, this longing has taken the form of “the search for the one” among complete strangers.
What I am talking about is that the longing of incestuous desire has acquired the modern name of anima (or animus) projection: when “the one” is found, we fall in love and enter a frenzied state towards the other person. As Robert Johnson would say, our 110-volt love turns into a supercharged 10,000-volt love that is not manageable, nor sustainable.
This frenzy will eventually dissipate and reveal beyond our initial idealization a real person underneath it, with its flaws and eccentricities that we have been blind to. At this point, the relationship will usually break because the enchantment is gone. And even when it does not, the incestuous longing will return and will be projected once again onto another person, who will have to be claimed as an illicit lover.
This phenomenon will repeat again and again and again, creating a series of disastrous heartbreaks and failed marriages, unless one seriously wisens up. What one needs to discover is that the common element to all these 10,000-volt love is the involvement of a psychic element.
In other words, we are not really looking for another person with all its imperfections and unique traits as such—otherwise the magic would not dissipate when the person reveals more of themselves. What we are looking for is a hook in the other person onto which we can hang a psychic projection. When the other person is a close enough approximation of this hidden psychic factor, then the projection can take place and restore a momentary intimacy that we have lost and can’t live without.
This repeated experience of heightened but provisional love is not only meant to put us in contact with more reality but also to promote a specific kind of self-knowledge, namely the realization that what we have been after is something qualitatively different than a flesh and blood person. What we are looking after is really a piece of ourselves that got lost somewhere, somehow, and can only be found temporarily at the heavy price of idealization.