Out of all the prohibitions on human sexuality put forward by the halakha, few have been as maligned in contemporary discourse as that of the prohibition on masturbation. Actually, our Sages actually constructed a relatively developed sexual ethic around masturbation-- but one that goes beyond masturbation per se and actually thinks about a broader category of exclusively self-serving sexuality we might call 'autoeroticism.' Autoeroticism is any and all sexual activity which occurs in a solitary context and this seems to be what the Sages legislated against. This is demonstrable by looking at the way that they talk about masturbation, the rationales given for its prohibition, and the exceptions that are made (for mutual masturbation).
There is no clear discussion of autoeroticism in the Tanakh or in the Mishna. The first reference we have to anything related comes from [Talmud Bavli Nidda 13a], which contains the famous and oft-misunderstood statement that, "in the case of a man, the hand that reaches below the navel should be chopped off." The Gemara tries to connect this to the story of Onan in [Bereshit 38:8-10]; however the two bear little comparison-- as the story of Onan clearly relates not to masturbation but to coitus interruptus. Morever, the Talmuds's concern is not masturbation precisely but rather ‘emitting semen in vain.’ To understand quite what that difference means, we have to look at the later halakhic sources. Rambam elaborates slightly on the Talmud’s anxiety about zera le’vatala by codifying that:
It is prohibited to cause the wasteful emission of semen; therefore, a person should not enter within [the vagina] but ejaculate on the outside [of it]. One should not marry a young girl who isn’t able to give birth. But those who commit adultery through the hand, and cause the emission of semen -- it is not simply that they have committed a great transgression, rather, one that does this should live under a ban of ostracism. For about them the verse speaks, “your hands, full of blood.” [Isa. 1:15], for it is as if they murdered someone.[Mishneh Tora, Sefer Qedusha, Hilkhot Issurei Bi’ah, Pereq 21, Halakha 18]Stronger language is hardly conceivable! Rambam clearly believes that masturbation is a very serious sin, one related to both coitus interruptus and the prohibition on marrying a prepubescent girl. However, the stress here is not on those two first things, but rather on what he labels m’na-afim b’yad -- adultery through the hand. Why is ‘adultery through the hand’ considered worse than these other two incarnations of wasteful seminal emission? What difference prompts the contrast that leads to the distinction made here? The answer is already in the text -- for Rambam doesn’t casually call masturbation m’na-afim b’yad. Rambam makes a key distinction on this issue: one takes place in the context of a relationship, and the other is solitary. As much as he has a certain anxiety about coitus interruptus and as much as he prohibits sex with a prepubescent girl for fear of ‘wasting’ semen, those are both things which happen in the context of a relationship. The much worse offense is that which occurs outside of any relational sexual dynamic; the real sin here, is autoeroticism.
Thus masturbation is banned, not simply because of zera le’vatala, but also because the autoerotic sexual pleasure of masturbation is inherently adulterous. Interestingly, the only text I could find which permits solitary masturbation does so with extreme caveats, and only in the condition that the choice is between committing adultery proper or masturbating. Even then, it requires immense teshuva:
It once happened that someone asked: What of someone whose urges have overpowered him and he is afraid that he will sin by sleeping with a married woman, or with his wife while she is a nidda, or any other of the arayot which are prohibited to him? If he is able to masturbate so that he not sin, and he then makes teshuva on it immediately, he may do so-- for is it not better for him to masturbate and not to sin with a woman?! But, he needs forgiveness (kappara) - he should sit on a block of ice in the winter or fast for forty days in the Summer. [Sefer Chasidim, Siman 176]This unusual passage indicates that the choice at hand is one of two types of adultery: m’na-afim b’yad (adultery with the hand) and m’na’afim b’isha (adultery with a woman). It decides that if one must choose, it is better to masturbate than commit one of the arayot (sexual offenses), but even the fact that the two potential sins are counted within the same category reinforces the reading that the real problem is not the emission of semen, but rather the autoerotic, solitary nature of masturbation.
The Zohar puts special emphasis on the spiritual and theurgical danger of autoeroticism. In a discussion of [Tehillim 5:5], Rabbi Yose asks, ‘Isn’t evil (ra) the same thing as wicked (rasha)?’ Rabbi Yehuda replies and says,
No. One is called wicked even if he merely raises a hand against another person but doesn’t actually hurt him-- but one is only called evil if he ‘wastes his way’-- defiling himself, defiling the Earth, empowering the impure spirit called evil, as is written, ‘nothing but evil all day.’ [Bereshit 6:5] He [one who masturbates] never enters the palaces nor gazes upon the face of the Shekhina, for on account of this, the Shekhina withdraws from the world. [Zohar I:57a]Unpacking the mystical rhetoric here, it’s clear that autoeroticism is considered something that distinguishes ‘evil’ from ‘wickedness.’ This sort of sin is beyond just bad behavior: for the Zohar, autoeroticism literally causes the Shekhina to leave the world. This is the application of the ‘adultery’ metaphor for the Zohar; the male mystic is meant to be a sexual partner to the Shekhina and thus autoeroticism is a form of adultery. Masturbation for the Zohar is a form of cheating on God, and leads to a literal distancing in the semi-romantic relationship between human and Divine. This assumption is what leads the Zohar to its reading of the Flood (mabool):
Rabbi Yitzchaq asked: Why did the Blessed Holy One punish the world with water, not fire or some other element? Rabbi Shimon answered: It is a mystery! For they wasted their ways (the people of Noah’s time masturbated), so that the upper waters and the lower waters failed to unite fittingly. Who has even ruined like this: male and female waters?! So they were punished with water - just like they sinned! The water was boiling, peeling off their skin, just as they wasted their ways with boiling water. A fitting punishment! As is written, ‘All the springs of the great abyss burst forth’ [Bereshit 8:2] -- these are the lower waters; and ‘the sluices of heaven opened’ (ibid.) -- these are the upper waters. Upper and lower waters.[Zohar I:62a]This Dante-esque vision of the flood is a bit terrifying, yet key to how the Zohar views the sin of masturbation. It is not just about wasting semen - again, it is about disrupting a relationship. The kabbalistic understanding of ‘lower waters and upper waters’ is a reference to the parallel sexual fluids (seminal and vaginal) involved in intercourse. Masturbation brought about the Flood, the Zohar says, because it precipitated the failure of the proper, relational sexual union. The sin here is the breakdown of relationship, the solitary focus of sexuality which deprives the world of the Shekhina and of feminine sexual energy.
These two readings of biblical verses lead to the most radical statement of the Zohar on the topic:
We have learned: Rabbi Yehuda said, ‘There is nothing in the world for which one cannot repent, except for this [masturbation]. There is no sinner who cannot see the face of Shekhinah, except for this one, as is written: Evil cannot abide with You—at all!” [Zohar I:219b]This is the harshest condemnation of autoeroticism in the entire corpus of rabbinic literature. This change, entirely without precedent, to seeing autoeroticism as a sin which cannot be repented for (something explicitly denied elsewhere) eventually becomes codified into the Shulchan Arukh. R’ Yosef Caro, influenced by the Zohar, only adds one phrase to Rambam’s codification of this section. The Shulchan Arukh quotes Rambam word for word on the subject of masturbation with the exception of the line, ‘...and this sin is more severe than any other in the Tora…’ This demonstrates the exaggerated influence of the Zohar on R’ Caro’s halakhic decision making-- but also the centrality of the concern about autoeroticism and its spiritual dangers to mainstream Judaism.
After seeing that autoeroticism is what lies behind the halakhic prohibition on masturbation, and witnessing the use of language that implies masturbation is tantamount to adultery (m’na-afim b’yad), perhaps the strongest evidence comes in the halakhic leniencies related to masturbation within a relationship. In order to reinforce that the issue is not masturbation per se but rather solitary autoerotic behavior, our Sages permit mutual masturbation within a halakhically-acceptable marriage. R’ Isaiah de Trani the Elder, a 13th century Italian Talmudist, writes that:
What was the action of Er and Onan that the Tora prohibits? It is that he committed it with the intent of not diminishing her beauty [due to pregnancy] and he didn’t want to fulfill the mitzva of procreation with her. But if his intent … is for his inclination and to satisfy his desire and his intent is not to avoid impregnating her, it is permitted, … he whose intent is to fulfill the desire of his inclination does not transgress as "all that a man wants to do with his wife he may do" [Talmud Bavli Nedarim 20b] - and this isn't called "wasting his seed"R’ de Trani clarifies that masturbation within a sexual partnership is not ‘wasting one’s seed.’ No clearer caveat to the halakha could be made that would illustrate that zera le’vatala is about autoerotic behavior and not necessarily causing oneself to emit semen. Other evidence for this same point is the rabbinic fear of zera le’vatala when it comes to involuntary nocturnal emissions. Again, the halakha sees nocturnal seminal emission as dangerous precisely because it is outside of the context of a relationship. Elsewhere, contemporary posqim like R’ Menachem Mendel Schneersohn (Tzemach Tzedeq) permit mutual masturbation within a relationship under the rubric of permitting non-procreative ejaculation in the case of medical danger.
All of these sources serve to demonstrate several key things: 1) the Sages take masturbation extremely seriously, 2) they do so because they see masturbation as the key behavior in a rubric of autoeroticism, and 3) as a result of the genuine fear being about solitary autoerotic behavior, they permit mutual masturbation within marriage while prohibiting other solitary behaviors such as nocturnal seminal emission.
Thus, we can, and should, uphold the prohibition. We should maintain that masturbation defies the acceptable bounds of a healthy and spiritually-productive relationship. If we are to do so, we must understand it as our Sages did - as autoeroticism, and put it into that context. Sexuality is not, in Judaism’s view, a solitary practice and as a result, our tradition views masturbation as spiritually problematic. Sexuality is something that happens within a relationship, and to separate the sex from the partnership that is its rightful context is detrimental to oneself.
Judaism possesses a sexual ethic which believes sexuality is about alterity-- and as a result, autoeroticism is spiritually and theurgically dangerous. Accepting this gives us a sound, internally consistent, and spiritually powerful rationale for preserving the prohibiton on (solitary) masturbation. We can use our tradition’s reservations about masturbation to form the cornerstone of a Jewish sexual ethic that prizes relationship and alterity, and rejects self-serving sexual pleasure.