Academically, we are obviously all morally opposed to incest and rightfully so. At the same time, there is an argument to be made in the Swiss case to let go what goes on privately in bedrooms.
   —Matthew Galluzzo

Is it wrong to wonder what’s wrong with incest? Will it sit still as an object of reasoned inquiry? If you offer an explanation for the rational underpinning of the taboo, will that satisfy the deep feeling of disgust that surrounds it? There is something about the question what is wrong with incest that suggests the more transgressive question is something wrong with incest. Aren’t we naturally averse to incest, anyway? If so, the pertinent question is not so much why is incest wrong as why is it prohibited?

I.
The modern situation.

A. Freud

For Freud, incestuous urges are at the beginning of human experience. This is famously expressed in his concept of the Oedipus Complex—love your mother, kill your father. The basic Freudian notion of sex and incest is this: A human being’s sexual character is as old as he or she is. Sexual character does not arrive unprecedented at the onset of puberty, ready to attach itself to a previously non-sexual subject. Rather, the formation of adult sexuality patterns itself on the circuits of pleasures and prohibitions established in the subject’s early years. This is an immanent account. If you begin your life suckling at your mother’s breast, achieving pleasure and nourishment simultaneously, that is your first erotic enjoyment. All later enjoyments are in some sense a variation on that first one. Pleasure is fundamentally incestuous, and without a denial of these initial pleasures it might remain so. This denial is provided by the exclusive daddy-mommy pairing; the child is pushed away from the parent he loves by the other’s rights. This prohibition is the point of departure for all prohibition; it is internalized in the subject’s development of a sense of shame and repression around sex. The incest taboo thus has its origin in the strength of paternal prohibition. It is this prohibitive character that motivates the displacement of sexuality into an arena of strangers. But in Freud, the original incestuous urge never dissolves. It is merely redirected towards an acceptable object.

B. Westermarck

The Finnish socio-biologist Edvard Westermarck provides a theory of the incest aversion that is commonly opposed to Freud by people who think Freud’s ideas are icky. His theory of reverse sexual imprinting suggests that an infant develops a sexual aversion to anyone, kin or otherwise, with whom they are reared in proximity. The ubiquity of this effect is a consequence of the workings of natural selection. “In this, as in other cases, natural selection has operated, and by eliminating destructive tendencies and preserving useful variations has moulded the sexual instinct so as to meet the requirements of the species.” The incest aversion exists as a biological safeguard against the deleterious effects of inbreeding.

Because of the scientific neutrality of Westermarck’s account, it serves as a blank slate for Freud’s haters. His theory doesn’t predict anything or offer judgements—it only observes what is evolutionarily successful on a species level. In neither his nor Freud’s theory is the incest aversion innate. Both develop in the first six years of a subject’s lifetime. Nonetheless, Westermarck is often read against Freud, within claims that incest aversion is a natural human mechanism, that incestuous feelings do not contribute to sexual experience. This overreading of Westermarck reveals a particular investment in an idea that our sexual urges must (should? necessarily?) match up exactly with whom we are told not to have sex with. What is the fear contained in this assertion? What exactly does it wish to deny? (When else would you deny the biological possibility of feeling something?)

In confronting Westermarck’s theory by itself, the two points of substantial difference with Freud are as follows: The positive content of childhood sexuality, and the role of prohibition in producing the aversion.

It is useful to think about the Oedipus myth in Westermarckian terms. Did he commit a crime? Does he have anything to regret or forget? Or is he only a casualty in the eyes of evolution? While Westermarck places minimal emphasis on psychology, he relies heavily on the alignment between sex and reproduction. The identity between natural (selection) and natural (aversion) requires the identity between sexual activity and genetic family. Without it, and with no prohibition to pin it into place, the aversion fails in its biological task.

II.
The medieval account

A. The peculiar account of Maimonides

As for the prohibitions against illicit unions, all of them are directed to making sexual intercourse rarer and to instill disgust for it so that it should be sought only very seldom…All illicit unions with females have one thing in common: namely, that in the majority of cases these females are constantly in the company of the male in the house and that they are easy of access for him and can be easily controlled by him…Consequently if the status of the woman with whom union is illicit were that of any unmarried woman…most people would have constantly succumbed and fornicated with them. However as it is absolutely forbidden to have intercourse with them, the strongest deterrents making us avoid this…men are safe from seeking to approach them and their thoughts are turned away from them. (Guide to the Perplexed III:49)

There is something in this account that inspires nervous laughter. Perhaps it seems as though Maimonides is tone-deaf to human nature. But he does make claims that a modern might readily adopt:

-The claim about the power imbalance inherent in familial relationship.

-The notion that the incest prohibition serves to curtail a sexual appetite which would be as voracious as we allow it to be.

What, then, provokes this instinctual embarrassment? Probably the assertion that without law, the taboo would disappear.

Maimonides and Freud are akin in that they both assert the role of prohibition in curbing incest and shaping desire. But they diverge over what mechanism instills the prohibition. Freud describes the formation of a taboo, which is a spontaneous human development of a sexual repulsion. Maimonides describes a divine law. Divine law is neither human nor spontaneous. It is a declaration pronounced by God. What does it mean that Maimonides imagines the bounds of a field of sexual desire in this way?

Maimonides is making two basic claims: that human beings are naturally inclined to incestuous behavior; that the divine law actually negates that positive urge, so that through the force of law such a desire does not even come to mind. This is characteristic of the notion of divine law that he shares with other Platonists. Any law seeks to produce collective harmony, but divine law also seeks to achieve moral perfection.

But doesn’t it also mean to produce friction with desire? Indeed, most of the time, it seems like prohibition exists to warn you against things you would like to do. Don’t eat bacon is a famous example. Don’t pursue your business on the sabbath day. Sometimes, though, it seems that divine prohibition exists to warn you against things you would never think of being drawn to. For instance, do not wear cloth of a mixed wool and linen weave (AKA shatnez). You might accidentally wear such a garment, but presumably you wouldn’t be driven to do so by desire. It seems like we will require a whole taxonomy to assess what divine prohibition does to desire. Does it repress it? Incite it? Redirect it? For now, we can begin classification based on the two variable categories of nature and morality, both of which at least stand apart from law, if not prior to it. We use these to mark the three objects of prohibition already mentioned as a. naturally appealing and morally neutral, b. naturally appealing and morally repulsive,¹ c. naturally and morally neutral.

This shifting terrain of the application of law to morality—sometimes it reinforces, sometimes it innovates (does it ever contradict?)—presupposes an existing standard of morality that operates without the instruction of the divine law. This relationship between a concept of natural morality and the divine law is of fundamental importance to Maimonides.

First of all, Maimonides does believe in a natural law, derived from the Talmudic notion of seven Noahide laws given by God to Noah after the flood. These laws apply to all of humanity and are designed simply to maintain social order. Though, it is worth noting, this ‘natural’ law is also decreed by divine command. Human nature without law is apparently boundlessly corruptible and given to violence. Thus it is fair to say that the natural law could be achieved by reason, if reason were strong enough to determine law.

The divine law is and can be achieved only by prophetic revelation (Thus, the primary function of revelation is political, in that it establishes legislation). It necessarily contributes something to human understanding that could not be achieved by reason. So there is a natural law, which is a law enforced by divine word in order to accord with nature, and divine law, which is a law enforced by divine word in order to transcend nature.

How does the restriction on incest fit into this model? It actually has a multi-faceted character: there are layers of incest prohibition in both natural law and divine law. Some sexual order is required by the order of the world, and some is required by the divine law for its purposes. These two tiers of prohibition may map well onto our categorization of desire: think of how you would place your mother, sister, or a beast compared to your brother’s wife. Probably fornication with your brother’s wife seems wrong but not necessarily gross. Which is to say, there are some sexual crimes for which even the stirrings of desire are crime enough, but others for which the circuit between feeling the urge and resisting the deed is not itself marked by guilt.

When Maimonides declares that the law of incest erases a fundamental tendency, which does he mean? Is human desire polymorphous enough to attach itself to beasts? Or is divine law strong enough to erase your lust for your wife’s sister?

B. Midrashic account of desire against the law

1 i wish i could

R. Elazar b. Azaryah says, from whence do we know that a person should not say, I do not wish to wear shatnez, I do not wish to eat pig flesh, I do not wish for any illicit union. Rather I do wish it, but what can I do? My father in heaven has decreed thus upon me. From the verse, “I will separate you from among the nations.” (Sifra Kedoshim 11:22)

Whether a commandment is naturally and morally neutral, naturally appealing and morally neutral, or naturally appealing (or is it repulsive?) and morally repulsive, this midrash encourages the subject of the law to draw a total distinction between his desire and the force of law. I wish I could (appealing) but the law forbids it (repulsive). In other words, exactly the opposite of the merging between law and desire that Maimonides describes. In an important passage in Eight Chapters, Maimonides describes this contradiction: a philosophical ideal of agreement between act and desire and a rabbinical ideal of the force of law over desire. He cites this midrash in illustration of the latter point. He resolves the contradiction by asserting that the rabbinical ideal agrees with philosophy in the realm of natural law (thus the midrash does not say, “would that I could murder and steal!”) but differs from it precisely in the realm of divine law. It is not clear to me that this view necessarily reconciles with the one later expressed in The Guide.

2 he allows, he permits

“The Lord frees captives”: What I have forbidden you, I have permitted you. I forbid you the suet of a domesticated animal, but I permit you the suet of a wild animal…I forbid you the wife of your brother, but I permit you levirate marriage.² (Leviticus Rabbah 22:10)

This midrash, with ten other examples which I’ve omitted, seems like a claim that the law does not contradict your desires. Not only that, there are several cases where the law is precisely constructed to permit the stirrings of desire, weird inversions or exceptions to the general case. The same forbidden pleasure is at once available to you, even if under sordid circumstances.

Contrary to Maimonides, these sources distinguish divine law by enforcing its difference from desire. It holds a completely different kind of power over the subject, one that demands the subject’s conscious power over itself. This is also contrary to Freud, whose incest taboo exerts itself by taking root in the unconscious. The reverence this midrashic law requires is one which maintains sharp awareness of its power. It never becomes as nature.

III. Antiquity

The law gives no reasons, describes no mechanism, though it does mark a desire, either in men or in God.

“The nakedness of your father and the nakedness of your mother you may not uncover; she is your mother, you may not uncover her nakedness!” (Leviticus 18:7)

The incest law affords particular access to the way in which divine law is prior to reason. Incest is before philosophy, before community. The law does not explain itself. The law simply asserts itself upon a pre-rational subject. She is your mother! Thus at once invoking and creating a feeling that this prohibition is something already known.

The law gives no reasons, describes no mechanism, though it does mark a desire, either in men or in God. The law gives no reasons because the law is not its own interpreter. Incest, dark and inexplicable, exists before and beyond its interpretation.

I wish you were like a brother to me.
   I wish my mother’s breasts had nursed you.
Then if I found you outside,
   I could kiss you.
   No one would look down on me.

Song of Songs 8:1

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¹The “most people” in Maimonides’ phrasing so implies moral reprobation.

²In the divine law, you are forbidden your brother’s wife under the law of incest, with the one exception of when your poor brother dies without an heir, you are then required to marry his wife in order to continue his line.

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