Rabbeinu Tam's Innovations

In our last post, we have established a new idea, introduced by the words of Rashi, that the sin of masturbation is one of “wasting seed” that could have been used to produce a child.  Rashi’s grandson, Rabbeinu Tam, as quoted in Tosfot Ketubot 39a then asks the following question:

"This does not seem (correct) to Rabbeinu Tam, as a young woman or an aylonit (women incapable of conceiving) one is allowed to have intercourse with them and it is not considered wasting seed, as long as it is done in the normal way of intercourse."

He continues:

"Prior to intercourse, one is certainly not allowed to use a Mokh (a contraceptive sponge of some sort) as it is not in the normal way of intercourse, and it would be (similar to) spilling semen on wood or stones, just the same as upon a Mokh, but after intercourse it would be permitted, as it is in the normal way of intercourse, similar to having intercourse with a young woman or an aylonit. And the woman who places the mokh inside after intercourse is not prohibited from destroying seed, since she is not obligated in the commandment to procreate…"

Rabbeinu Tam has now introduced several completely new concepts.

1. Once the idea of “destroying seed” was established by Rashi, Rabbeinu Tam was forced by his understanding of Rashi’s words to answer a new contradiction.  How is it that one is allowed to have sexual relations with a woman who cannot conceive?  (Recall, that according to the Rambam, and all who preceded him, this is not a problem at all, because they never heard of this prohibition of “wasting seed”, as we extensively explained in our previous posts) So Rabbeinu Tam came up with a new concept to explain this contradiction.  That any ejaculation that occurs “in the normal way of intercourse” is considered OK even if it can’t result in pregnancy.  However, any ejaculation that cannot result in pregnancy that does not occur in the “normal way of intercourse” would be prohibited.
2. Rabbeinu Tam introduces the concept that there is a prohibition of wasting seed, and he traces its origin to the mitzvah of procreation.  Somehow, the mitzvah to procreate also entails a prohibition to “destroy seed”
3. Since the prohibition is related to the mitzvah of procreation, Rabbeinu Tam therefore can differentiate between men and women.  A man cannot “destroy seed” while a woman can.

Let us analyze these ideas of Rabbeinu Tam a little further, because they have pretty much become the basis of so much Halachah in the realm of reproductive Halachic discussions for the next 800 years or so.

The Normal way of Intercourse

This new concept, as you can easily imagine, opens up a gigantic can of worms. Let me remind you of how easy Halachic life was in the pre-Rabbeinu Tam days.  As we saw in the Rambam, as long as you don’t ignore your obligation to procreate, and as long as you are in an appropriate sexual relationship, there are no more regulations regarding “spilling seed".  I quoted this before, and I will quote it again:

 "A person’s spouse is permitted to him, therefore any (sexual) activity that he desires to engage in with her, he may engage in it. He may have sexual relations with her at any time he desires, and he may kiss her on any part of her body that he desires, he may have sex with her in the normal way (vaginal) or not in the normal way (anal), he may have sex by using the (normal) limbs of the body or even not the (normal) limbs (Rambam, Mishna Torah, Laws of Forbidden Relations 21:9)"

However, now we suddenly have something new. If one engages in any form of extra-vaginal sex and ejaculates during sexual activities with his wife, he has now violated this new law.  In fact, this even governs what contraceptive devices he can use.  While according to pre-Rabbeinu Tam poskim, the use of barrier contraception was considered fine in cases where pregnancy was unhealthy for the woman, suddenly the use of barrier contraception is now prohibited during intercourse.  The Halachic ramifications of this idea are immense.  This law went from one that encourages procreation and sexual morality, to one that regulates what type of sex is OK between a husband and wife.  It is nothing short of astounding. 

Wasting Seed = Violating Mitzvah of Procreation

This idea is just about as revolutionary as the first.  In all other Halachic discussion in pre-Rabbeinu Tam days, it was well understood that engaging in sexual activities that are designed to avoid fulfilling the commandment to procreate were discouraged, and compared even to murder.  However, it was also understood that as long as one does not ignore his obligation to populate the Earth, sexual activities in appropriate relationships were perfectly fine.  That is because no one ever heard of this prohibition of “wasting seed”.  But now, Rabbeinu Tam tells us that the Torah’s command to procreate includes a prohibition of wasting seed.  Exactly how one derives this from the verses in the Torah is unclear, but this is what he says.  Now this “prohibition is elevated to a “D’Oraytah” a prohibition with an origin in the Torah.

Men Only

The third logical outcome of Rabbeinu Tam’s opinion, is that this prohibition of wasting seed only applies to men, who are commanded to procreate, and not to women who are not considered obligated to procreate.  (The origins of this differentiation between the genders is beyond the scope of this blog post). If that is the case, we left with a strange dichotomy between the two individuals involved in this heterosexual encounter between a woman and her spouse.  She is not prohibited from any act, even “wasting” his seed, but he cannot do anything other than sex that concludes with intra-vaginal ejaculation.

The Other Ba'alei Tosafot Take on Rabbeinu Tam

One of the primary problems with Rabbeinu Tam's approach, is that it raises so many contradictions and difficulties with other passages in the Talmud.  After all, when the Rambam permitted anal intercourse and all sorts of sexual practices (in an appropriate relationship) including using all parts of the body for pleasure, he was quoting the Talmud itself! So how do we understand this?

These questions were of course raised by several Ba'alei Tosafot who followed after Rabbeinu Tam (Talmudists, mostly from France and Germany, during the period starting from around the time of Rabbeinu Tam himself in the mid-12th century for approximately the next 200 hundred years until the early 14th century.  These Talmudists all contributed to the "tosafot" which are composed as additions to the back and forth arguments in the text of the Talmud itself).  The two most famous to deal with this issue are Rabbi Issac ben Samuel of Dampierre, France (1115-1184) also known as the "Ri Hazaken" and Rabbi Isaiah di Trani of Venice Italy (1180-1250) also known as the "Tosafot Rid".

Both of these Ba'alei Tosafot had a problem.  They at first understood the words of Rashi the same way that Rabbeinu Tam did, which is that there is an inherent problem with "wasting seed".  However, they needed to reconcile this with the fact that in so many instances, the Talmud explicitly allows ejaculation when pregnancy is not going to result.  Bottom line, they could not accept Rabbeinu Tam's interpretation.  What they did essentially, was explain Rashi the way I did in the last post.  That wasting semen is only an issue when one does it regularly in an attempt to avoid fulfilling the mitzvah of procreation. However, when it is done in the usual course of normal permissible sexual activity, there is no prohibition against "wasting seed". In their words:

... Furthermore, Rabbi Isaac (R' Isaac ben Samuel of Dampierre) says, it is not considered an act of Er and Onan unless a person intends to waste seed and does so consistently (which one might do if his intention was that his spouse should not conceive and thus him not fulfill his obligation to procreate) However if as a random matter of course, when a person may desire to engage in atypical intercourse with his wife in a different way (e.g. anal intercourse) it would then be permitted, as the Talmud teaches (Nedarim 20b) Whatever a man desires to do (sexually) together with his wife he may do ... (Tosafot Yevamot 34b) 

Here, Rabbi Isaac is explicitly permitting masturbation and other sexual practices and sees no problem with "spilling seed" unless it is done on a regular basis with the intent of not fulfilling one's obligations of procreation.   As long as it is done in the context of an acceptable sexual relationship and it is not habitual. Rabbi Isaiah di Trani says it more clearly (discussing the Talmudic ruling allowing one to prevent pregnancy by the withdrawal method - ejaculating externally - in cases where pregnancy can be harmful to the woman):

"...and if you ask, how could it be that the Rabbis permitted to ejaculate semen and do exactly the actions of Er and Onan (as described in the bible they did the "withdrawal method").  The answer: What are the actions of Er and Onan that the Torah prohibited? Anyone whose intention is that his wife does not get pregnant in order that her beauty not be diminished, and he does not desire to fulfill his obligation to procreate with her. But if his intent is that she should not be brought into (a situation of) danger it is permitted. and so to if his intention is (simply to) fulfill the desires of his heart and his intention is not to prevent pregnancy it is also permitted ... someone whose intent is to fulfill his sexual desires is not transgressing (the sin of Onan) because whatever a person wants to do (together with) his wife he may do, and it is not considered "destroying seed" for (if it was considered destroying seed) one could never have sexual intercourse with a younger woman or an aylonit, or an infertile woman" (Tosfat Rid, Yevamot 12a) 

Here Rabbi Isaiah di Trani again explicitly permits masturbation and spilling seed, as long as it in the context of a permitted relationship.  He is clearly rejecting the possibility that Rashi meant that wasting seed in and of itself is some sort of prohibition. This is of course consistent with tyhe simple meaning of all of the Talmudic passages we have studied so far.

So again, these two great scholars, even after Rashi's comments, still understood the Halachah to be exactly the way we described the Rambam, before of course the sneaky phrase crept into the text of the Rambam sometime in the 13th century - which we discussed here. Despite their attempts though, Rabbeinu Tam's words were going to have more influence on the future development of Halacha.  In the next post I will start tracking how this happened. 

A New Idea Arrives Upon the Halachic Scene

Now that we have established the opinion of the Rambam, it is time to track how a completely new understanding of the "prohibition" of masturbation came upon the Halachic scene, and pretty much replaced the traditional understanding of the Torah and Talmud up until somewhere in the middle of the 13th century.  However, before I begin this discussion, I believe it is important to explain that the Rambam's understanding was by no means limited to the Rambam.  It was the widespread understanding in the Rabbinic world.

For example, the Semag (Sefer Mitzvot Gadol - early 13th century) that early Ashkenazic Halachic work written by R' Moshe of Coucy in France, demonstrates that the understanding of the Rambam was widespread.  The Semag lists masturbation during his discussion of practices that could lead one into a life of sexual immorality.  In general, the rabbis of this time both in Ashkenazic countries such as France, and in Sephardic countries such as Spain advised that one should avoid practices that lead one to live a life in pursuit of sexual pleasure. Among the prohibitions listed together with masturbation are things like flirting, gazing upon women, touching, etc...  Other early Halachic works such as Sefer Ha'eshkol (R' Abraham ben Isaac of Narbonne - 12th century) also condemned the practice because they felt that one who deliberately engages in such practices could lead to sexual immorality.  This was the general understanding, and it was generally accepted.

The reason why all of this is important, is that there is no inherent prohibition of "wasting seed". If that is the case, then when an ordinary young man is aroused, which is completely normal and common, and he deals with this arousal by masturbating, no terrible sin has occurred.  When a loving couple engages in sexual activity, and a man ejaculates, no terrible sin has occurred either.  In fact, the couple has only engaged in a loving activity which is to be expected of a healthy couple.  The problem is only when one engages in a lifestyle that seeks sexual stimulation, and when one spends his time pursuing such matters.  In such instances, engaging in masturbation while pursuing immorality is the issue these rabbis were discussing.

It is also important to point out that the views of these Rabbis and of the Talmud itself were stated in a world in which attitudes toward what constitutes sexual immorality were very different from what we find today.  the topic of exactly how to apply these ideas in modern times will have to wait until we complete our halachic discussion.

The New Concept - "destroying seed"

One of the most famous Talmudic and halachic scholars of all time, is Rabbi Shlomo ben Yitzchak, known as Rashi. He was famous for many things, but on a literary level, he is well known for his brevity and his ability to convey big ideas in just a few words.  so many times, extremely difficult Talmudic concepts are explained by Rashi in a short simple sentence fragment that somehow manages to illuminate everything.  Occasionally though, his brevity also leaves a lot of room for further interpretation.  Hence, numerous books have been written and Talmudic discourses expound for thousands of pages just what did Rashi mean when he said this or that.

There are two statements of Rashi that completely changed the Halachic understanding of masturbation for the remainder of Halachic history. I will state that frankly I am not completely sure if that was his intention, but so it was.  In Rashi's commentary to R' Yitzchak Alfasi's (known as "the Rif") halachic work in Shabbat chap 14, 108b Rashi makes one of his short statements of explanation.  The Rif himself quotes the Gemara in Niddah that we have been discussing this whole time, which he almost certainly understood the same way that the Rambam understood.  The Rif mentions the comparison to murder, which almost everyone until the time of Rashi understood to mean two things, that 1) not engaging in having children was similar to murder and 2) it was meant to sound scary. However, Rashi comments as follows:

"They (those who engage in masturbation) are destroying ("mashchitim") seed that could become children"

The second comment of Rashi is in Ketubot 39a.  There the Talmud is discussing the permissibility to use a form of contraception called a "Mokh", which is some sort of sponge placed in the vagina during intercourse as a barrier. The Gemara permits its use when pregnancy can be a health concern for the woman in question.  The simple understanding is that may have sexual relations with his wife even though they will not be fulfilling the mitzvah of procreation.  Rashi there states:

"They are permitted to use a "mokh" and they are not (considered to be) like they are destroying seed" 

The simple understanding of Rashi, IMHO, is that he is also referring to the concern that one is obligated to fulfill the mitzvah of procreation.  When he uses the term "destroying seed" he gives it away when he states, "that could become children".  In other words, he is stating the same understanding as everyone else.  The reason he chooses the term "haschata" (destruction) is because in the story of Onan in the Torah this term is used as well.  The "destruction" there has been understood to mean that by not "building" the world (i.e. having children) one is passively engaged in "destruction."  The reason why it is difficult to imagine that Rashi meant the destruction of the seed itself, is because there are so many examples that we have discussed in which sexual activity and ejaculation is permitted even though pregnancy is impossible.

However, this is not how Rashi has been interpreted by most Halachic authorities ever since. They understood that Rashi is trying to teach us that there is some prohibition literally in "wasting seed'.  This is revolutionary.  Especially since it is nowhere to be found in the Torah or Talmud that "wasting seed" i.e. ejaculating semen outside of a woman's body is some sort of problem. So, a brand-new sin has arrived on the Halachic scene.

Rashi's grandson, Rabbeinu Tam, was the next step in the development of this new concept.  We will analyze his opinion in our next post and discuss the termendous influence of Rabbeinu Tam on the future development of the Halachic process regarding masturbation.

Rambam's Opinion and the Mysterious New Phrase

 I have already described the opinion of the Rambam in this post here.  However, that was several years ago, and I need to do a better job. The big surprise of this post is at the end, so it will be a reward for those who are patient enough to read the whole post! Warning: you will not understand the surprise if you skip to the end without reading the lead-up. 

Understanding the Rambam properly is a crucial step before we begin to describe the opinions of the standard Rishonim (The Rabbinic literature from roughly the 11th century through the 16th century), as the Rambam is vastly different from what we find in the other Rishonim.

The Rambam's opinion on this matter can best be understood by dividing his ideas regarding masturbation into three categories.  1) Health reasons, 2) ejaculation to avoid fulfilling the obligation of having children, 3) deliberate stimulation of sexual desire in inappropriate contexts, which often includes masturbation can lead to sexual immorality.

Health Concerns

The Rambam states as follows:

"Semen is the vigor of the body, its very life, and the light of the eyes, and it’s too frequent emission sets decay in the body, wastes its strength, and ends life itself, which is as Solomon in his wisdom said: "Give not unto women thy vigor" (Prov. 31.3). Whosoever indulges in sensuality ages before his time, his strength fails him, his eyes become dim, a foul odor issues from his mouth and from underneath his arms, the hair of his head, eye-brows, and eye-lids fall out; the hair of his beard, under his arms and his feet grow heavier, his teeth fall out, and many more ailments besides these come upon him. Doctors of medicine said: "One in a thousand die of other diseases, and the rest of the thousand from overindulgence of sex. Therefore, must man be careful in this matter, if he desires to lead a good life. He should not yield to an urge save if his body be in good health and exceedingly vigorous, with involuntary erection despite diversion, and a pressure on the genitocrural arteries accompanied by warm wave over his body, when there is a hygienic need of relief. But he should not still an urge when sated and not when hungry, but after the food in his bowels be digested. Care should be taken, before and after, whether there is a need of elimination. Neither standing nor sitting; neither in the bath-house nor on the day of bathing; neither on the day of blood-letting nor on the day of departing for or returning from a journey; neither preceding nor following all these.(Rambam, Mishna Torah Hilchot De'ot 4:19)"

In this passage the Rambam is quoting from his medical knowledge.  This was the accepted view of the time amongst the medical world, mostly influenced by Plato, Aristotle, Galen and others.  That excessive ejaculation deprived the body of its strength and caused illness, but that holding on to too much semen without ejaculation was unhealthy as well.  The relationship between eyesight and the "male seed" was also widespread in the ancient world.  So, one reason to avoid masturbation was health related, which according to Maimonides, is therefore also a binding religious precept.  Therefore it is included in his book of Halacha, the Mishna Torah.

Interestingly, the Rambam's concern for health may also sometimes require that one ejaculate. As he states:

"Likewise, in sexual relation there shall be no intercourse save when it is of benefit to health, or to sustain species. One should, therefore, not yield to every urge, save when knowing that emission of semen is a helpful means medically or to sustain species. (Rambam, Mishna Torah Hilchot De'ot 3:2)"

In the Rambam's medical writings he describes how semen retained for too long can be dangerous, and sometimes must be ejaculated for health reasons, in this he echoes the words of Galen and others.

Avoiding Procreation

The second reason why the Rambam holds that masturbation is problematic is when it is done for the purpose of preventing the fulfillment of the obligation of having children.  The origin of this is obviously the story of Onan in the Torah.  See our discussion here regarding the details of the Biblical account.

When the Rambam introduces the prohibition of masturbation itself, it is in this context of sexual relations when done as part of a person’s intent to avoid having children to fulfill the Mitzvah of P'ru U'rvu (building a family).  This is clearly because the Biblical origin of the idea is from the story of Onan, as we described in our previous post on this topic.  Here is how the Rambam himself introduces the topic:

It is prohibited to ejaculate semen for naught, therefore a person should not have intercourse and then withdraw to ejaculate, one should also not marry a woman too young to give birth to a child. However, those who have sexual relations with their hands and thus ejaculate (outside of a woman's body) not only are they committing a prohibited act, but one who does should be isolated (from the community) and regarding such people it is said (Isaiah 1:15) "Their hands are stained with blood" and it is as if he is guilty of murder.  (Rambam, Laws of Forbidden Relations 21:18)

Similarly, the Rambam states in his discussion of the laws of marriage and the mitzvah of raising a family:

A man should not marry a woman (known to be) infertile, or postmenopausal, or an aylonit (a woman who due to an endocrine disorder does not ever develop feminine characteristics) or a woman too young to carry a child unless he has already fulfilled the mitzvah of having children or if he has another wife from whom he will fulfill this mitzvah (Rambam, Mishna Torah, Laws of Marriage 15:7)

When the Rambam writes, "having sexual relations with their hands" he is translating the term in the gemara "Niuf Beyad U'beregel" that is used by the Talmud.  While others understood this to be masturbation, the Rambam did not, he understood that this meant sexual practices that caused ejaculation by contact with other body parts like the hands and legs of another person.  This would be another sexual practice that the Rambam would disapprove of when done in the context of trying to prevent pregnancy, when someone has not yet fulfilled the mitzvah of having children.  The Rambam states this definition clearly when listing prohibited sexual acts:

One who has sexual intercourse with one of the prohibited relations, or embraces her, or even touches a part of her body in order to derive pleasure, regardless of which part of her body, such as when (people rub each other) with their hands or legs, and this is the type of abomination that the Sages call those who commit adultery with their hand or foot (Mna'afin beyad U'beregel) (Rambam Pirush Hamishnayot, Sanhedrin 7:4) 

I quoted these three passages in succession so that you can fully understand Maimonides reasoning.  The progression of his reasoning is as follows: 

1. The origin of the prohibition is the Biblical story of Onan
2. In this story, the prohibition was because Onan engaged in sexual activity with his wife by ejaculating after withdrawal and thus refused to fulfill the mitzvah of having children
3. Therefore, any type of intercourse, including marrying a woman too young to have children, which is meant to allow for sex while avoiding one's obligation to procreate is forbidden.
4. this includes sexual practices such as mutual masturbation and causing ejaculation with your hand, when done to prevent the fulfillment of the mitzvah of procreation, is akin to murder
5. It should be obvious that the comparison to murder is because the person is guilty of not populating the world as God intended.
6. however, if one has already had children, this prohibition does not apply

Leading to Sexual Immorality

Item number 6 in the previous list leads us to the third reason that Maimonides has a problem with the practice.  Maimonides is concerned that when one intentionally arouses oneself and thus brings himself to eventually satisfy his sexual urges and he ejaculates not in the context of having sex.  In the Rambam's discussions of these topics, masturbation is almost always discussed in the context of other sins which are not necessarily prohibitions but are very much discouraged by the Rambam due to concern for general immorality and where these practices may ultimately lead.  After discussing the laws mentioned above, the Rambam takes the opportunity to spend the remainder of the chapter to explain this idea.

He goes on to discuss not engaging in practices that are meant to arouse oneself, but rather one should spend his time with holier pursuits.  He discusses needless flirting with the opposite sex, watching women when they are engaged in private activities, even observing women's clothing in such a way that it arouses oneself.  He discusses not following women around the market or hanging out near places of ill repute. Maimonides then describes that for someone single and not in a proper relationship, these activities can lead to illicit behavior.  I am not quoting this directly because it is long, but you can read it yourself in Rambam Mishna Torah Laws of Forbidden Relations 21:19 - 32).  In this respect, Maimonides groups masturbation along with the activities that one engages in that can lead him down a bad path.  Instead he recommends that we spend our time in appropriate activities.

Nowhere in any of the writings of the Rambam do we ever find a reference to "wasting seed" as if there is an inherent problem with ejaculating outside the body of a woman in and of itself. It is always a problem only because it is either part of a practice that can lead one astray, or because one is not in a healthy and proper sexual relationship so that he could go down a bad path, or because he is deliberately not fulfilling the mitzvah of procreation.

This leads to one last fascinating statement of the Rambam.  That is that when one IS in a healthy appropriate relationship, and one has fulfilled the mitzvah of having children, he states as follows:

"A person’s spouse is permitted to him, therefore any (sexual) activity that he desires to engage in with her, he may engage in it. He may have sexual relations with her at any time he desires, and he may kiss her on any part of her body that he desires, he may have sex with her in the normal way (vaginal) or not in the normal way (anal), he may have sex by using the (normal) limbs of the body or even not the (normal) limbs (Rambam, Mishna Torah, Laws of Forbidden Relations 21:9)"

If you have been following me until now, you would see clearly that the Rambam almost certainly wrote this specifically to permit any activity including not only anal intercourse, but even using other limbs, even if such practices result in ejaculation outside of a woman's body!  This is what the Rambam prohibited when done for the purpose of avoiding the mitzvah of procreation, or in a context outside of marriage when it leads to promiscuity.  But in the context pf marriage it is completely permissible!

For the first 150 years or so, this is exactly how every single manuscript of the Mishna Torah read.  However, suddenly, at some point during the 13th century, a phrase was appended at the end of the paragraph I just quoted which reads as follows:

.... he may have sex by using the (normal) limbs of the body or even not the (normal) limbs as long as he does not spill seed for naught!

Perhaps the two most authoritative versions of Mishna Torah available today, The Frankel edition of the Rambam, and R' Kapach's edition BOTH point out that this phrase was a later addition.  This phrase turns the Rambam completely upside down, and makes itself contradictory.  It also has been used by Halachic texts from the 13th century onward to lend support to the MUCH later idea that the prohibition of masturbation was a problem of "spilling seed" and "wasting seed".  The later authorities almost all pointed to this Maimonidean text that was never really written by Maimonides, and in fact was contrary to what he was trying to teach.

Even if this text was authentic, which it is almost certainly not, the only way to understand it would be to say that the Rambam meant "as long as he doesn't spill seed for naught ... as Onan did, to avoid pregnancy when one is still obligated to have children."  But if you do not like my potential explanation, it does not matter, because we don’t need to explain the intent of this passage as Maimonides did not write it.

So why did this text land in the middle of the Rambam? While I cannot answer that for sure, it certainly is not coincidental that the entire tide of halachic discourse on this subject changed dramatically during the years after the Rambam.  In my next post, I will start with the opinions of Rashi and Rabbeinu Tam and continue from there. After that I plan on taking you through the very heavy influence of the Kabballah on this issue, and the influence of the science of the day, and of Christianity.

The Real Reason the Talmud "Prohibits" Masturbation

I would like to continue where I left off in our discussion of masturbation several years ago.  So many people have written to me over the last few years in appreciation of my blog and asking me when I would start writing again. It was this overwhelming and very flattering response to my blog that now has led me to continuing this endeavor.  So much has happened in the world since 2017, and the need for sensible Halachic discussions of medical subjects has only grown more and more intense.  I hope to do my small part in bringing the ideas of Rationalist Halachah into a broader audience.  Comments and suggestions for future topics are very much welcomed, and the real purpose of this blog is to stimulate intelligent discussion.  I want to learn, much more than I want to teach.

In my last post, I demonstrated that the "sin" of HZLV has nothing to do with murder.  I ended with the question of why the rabbis of the Talmud compared it to murder and I promised to answer that in future posts.  More importantly, I must describe exactly what the "sin" is and what the "prohibition" is and its true origins.  Since it is clear that nowhere in the Torah (see this post here) is there written a clear prohibition of masturbation, the origins of the sin must therefore be defined.

In order to do this, an analysis of the Talmudic sources is necessary.  Please go back and review my previous post regarding the gemara in Nidda 13a-b.  I believe that we can begin to understand what the gemara in Niddah was prohibiting, if we go back to the meaning of the words, "Hotza'at Zera Le'Vatalah".The term is usually translated as "Emitting Seed for naught".  It is important to note that the only place in Talmudic and Mishnaic literature where this term appears is in the gemara in Niddah which we just mentioned. In the medieval halachic literature, this term became understood to mean that "wasting" semen is a sin, meaning any emission of semen for purposes other than procreation, and thus akin somehow to murder.  We have already mentioned numerous examples in this blog that prove that the talmud clearly did not understand the term in this manner. I mentioned three such proofs in this post here, Those proofs were a) the Talmud's explicit permission allowing for anal intercourse with one's spouse, b) The allowance of the Talmud for ejaculation as part of an exam to determine one's medical status c) The talmud's understanding that unintentional seminal emissions could be a positive thing.  I will add a few more proofs here, as I believe they are important for the readers of this blog to keep in mind.  

1. That the Talmud, according to almost all commentaries and poskim don't consider the abortion of a fetus to be murder.  While it is under most circumstances prohibited by Jewish law, with very few exceptions, it is accepted that the origins of the prohibition are not from the laws against murder.  We dealt with this subject at length back in my series on abortion here. I recommend that you read the entire series if this topic interests you.  If abortion is not akin to murder, than it would be absurd to the extreme to consider masturbation akin to murder.
2. In Yevamot 34a (and other places) the Talmud asserts that a bride never becomes pregnant from the first intercourse.  Leaving aside the questionable scientific correctness of that statement, it was the belief of the Rabbis that this is the case.  Clearly, they were not concerned about "wasting seed" when a new husband has intercourse with his spouse for the first time.
3. In Yevamot 34b, the gemara brings a beraita from Niddah in which Rabbi Eliezer recommends that for the 24 months after a woman has a child (during which she would be breastfeeding the child) that one should practice what is now called the "withdrawal method"(to have intercourse and withdraw and ejaculate externally).  Rabbi Eliezer was concerned that should she get pregnant during this period, she would not be able to nurse her child and carry the pregnancy at the same time.  Note that this is the same Rabbi Eliezer who said in Niddah: "anyone who holds his penis and urinates, it is considered as though he is bringing a flood to the world. ... It is preferable that people cast aspersions about his children that they are mamzerim, and he should not render himself wicked even one moment before the Omnipresent."  Clearly, even the most stringent of the rabbinic opinions quoted by the gemara did not believe that the prohibition had anything to do with "wasting seed".  
4. Yevamot 12b (and other places) allows normal intercourse and the use of contraception with a spouse for whom it is dangerous to get pregnant
5. normal sexual intercourse with one's spouse who can not have children is permitted
6. normal sexual intercourse with a woman who is post menopausal is permitted 

Once we have established that the "prohibition" has nothing to do with "wasting seed", we can now understand the true meaning of the gemara and why the act of masturbation was considered sinful. The gemara started off with the prohibition of needlessly touching one's genitals.  The gemara discussed with disdain the practice of purposefully arousing oneself.   The gemara stated clearly that these prohibitions did not apply to touching one's genitals when there was no concern for self arousal, and it also clearly stated that self arousal was not a problem when it is in the context of marriage, when there would be no sin involved in the fulfillment of sexual pleasure with his spouse. It is thus a no-brainer to understand that the issue here is not one of "wasting seed", but rather the rabbis are teaching us that arousing oneself in a context which can lead to improper sexual behavior is wrong.

The term "Le'Vatalah" does not mean wasting in the sense that there is a concern that semen is spilled that will not result in pregnancy.  Rather it means that the person engaging deliberately in this behavior is taking his normal sexual sexual drives, which can and should be used in the proper context of a healthy sexual relationship, and he is wasting it for purposes that can lead him astray.  Eventually this can lead to terrible things if one makes a habit out of satisfying his sexual urges in unhealthy ways.

The various statements then follow logically.  The Talmud goes on to compare masturbation to the three cardinal sins, idol worship, murder, and adultery.  While this sounds quite severe, no reasonable person would imagine that this is meant to be taken literally.  The talmud makes so many such statements, for example:

1. Bava Metziah 58b: the tanna taught a baraita before Rav Naḥman bar Yitzḥak: Anyone who humiliates another in public, it is as though he were spilling blood. 
2. Sotah 46b: Rabbi Yoḥanan says in the name of Rabbi Meir: Whoever does not accompany a guest as he leaves one's home or will not allow himself to be accompanied is like a spiller of blood
3. Shabbat 105b: Rabbi Shimon ben Elazar says in the name of Ḥilfa bar Agra, who said in the name of Rabbi Yoḥanan ben Nuri: One who rends his garments in his anger, or who breaks his vessels in his anger, or who scatters his money in his anger, should be like an idol worshipper in your eyes, as that is the craft of the evil inclination. Today it tells him do this, and tomorrow it tells him do that, until eventually, when he no longer controls himself, it tells him worship idols and he goes and worships idols.

The list of such statements can go on forever, so I just brought some famous examples of similar statements.  The third quote, from Shabbat 105b though, I do believe is especially relevant for our discussion.  Rabbi Yochanan ben Nuri is teaching us a very similar lesson to the one being taught in Niddah regarding deliberate masturbation in a context that can lead one down a destructive path.  Just as breaking vessels in anger is not technically speaking a prohibition in and of itself (though it may be considered a violation of Bal tashchit - deliberate waste) such behavior, if it becomes habitual, can lead one down a destructive path.  Similarly, masturbation, when done in an inappropriate context, can lead one down a dangerous path.

I will go out on a limb here and state as follows.  The proper expression of sexuality in the viewpoint of the rabbis is within the context of marriage (or at least, within the context of an adult, consenting, committed relationship if one allows for certain historic and legal circumstances, see Zvi Zohar here).  This is why the rabbis encouraged marriage at a young age, so that the often promiscuous sexual behavior that is likely to occur when youths remain unwed would not lead them down a destructive path.  I am not currently recommending that our youth get married at an inappropriately young age in order to avoid this problem.  However, it is extremely common for a healthy young man to have a normal sexual urge, and due to this stimulation to masturbate.  If a young man with a normal and healthy sexual drive is taught what safe, healthy, appropriate sexual interactions are supposed to be, then there is no reason that this act should lead in any inappropriate direction. In fact, when properly directed, it will hopefully give him an opportunity to consider what a healthy sexual relationship is.  One day, he will find the right partner and engage in what is supposed to be one of the most rewarding aspects of a proper adult relationship.

Instead, too often, what we teach this young man is guilt and shame. No attempt is made to teach him that sexual urges are a normal part of being human.  No attempt is made to teach him that seeking healthy fulfillment of these urges is not only acceptable but encouraged by God.  Does this make him more likely to take the wrong path and seek fulfillment of sexual desires inappropriately?  Will this lead him to be more likely to commit actual sins?

Modern science does not view masturbation as a sin or a problem at all.  It is considered normal healthy behavior.  Therefore, if a young Orthodox man was feeling guilty about masturbating and he went to speak with a secular trained therapist, he or she would tell him that this is normal and not to worry about it.  He can then be taught about normal sexual behavior and thus deal with his guilt. If instead he is taught that what he has done is terrible sin akin to murder, he will then be stuck in a terrible spiral of feelings of shame, self hatred, weakness and maybe even anger. I could not find data to support the idea that these feelings can certainly lead to acting out, leaving the path of Torah, promiscuity  or worse.  But there certainly is a lot of anectodal evidence that supports this.

One such story I advise that you read is to be found here.  In this case, the guilt regarding masturbation did lead to acting out of anger and poor social behavior.  Fortunately, this young man was able to get appropriate help.  What struck me the most, was how after appropriate treaching, he learned to respect women appropriately.  This article here can also lead you to more information on this subject. I also recommend checking out this blog post which can lead you to more information as well.

This is supposed to be a halachic blog though, not a social commentary on Orthodoxy, so in my next post I want to get back on track.  Now that we have dealt with this topic in the rabbinic period, we will move on to the period of the Rishonim.