How is a Baby Made? More specifically, what determines the future characteristics of the child? One answer emerges from the story of Yaakov’s breeding of the sheep, an answer that seems to be endorsed by the Talmud: a child’s character is shaped by what the mother and father were thinking and doing at the time of conception.
The Gemara in Nedarim (20a-b) has an extended discussion about which, if any, acts of marital sex are discouraged or forbidden. Yochanan ben Dahavai states that the reason children are born lame, mute, deaf, or blind, is because husband and wife were engaged in improper sexual behavior with their bodies (certain sexual acts), their ears (what they were listening to), their mouths (where they were kissing), or their eyes (where they where looking). This statement parallels the belief, widespread in the ancient world, that the thoughts or actions of the parents can imprint themselves on the fetus being conceived. In his book “Natural History,” Pliny the Elder (1st century CE) states:
… [T]hat a great many accidental circumstances are influential (that is, exert an influence on the fetus)—recollections of sights and sounds and actual sense-impressions received at the time of conception. Also a thought suddenly flitting across the mind of either parent is supposed to produce likeness [in the fetus] (7:2).
This understanding of fetal development is implicit in the story of Yaakov and the rods (30:37-39). To ensure that Lavan’s flocks give birth to striped and spotted sheep, Yaakov peels white streaks in wooden rods and places them where the sheep will see them when they copulate. And, lo and behold, this works:
And the flocks conceived before the rods, and brought forth sheep striped, speckled, and spotted (30:39).
Bereishit Rabbah (VaYeitzei, 73:10, Vilna edition) illustrates the validity of this science in the case of humans with the following colorful story:
There is a story of a black man who was married to a black woman, and she bore him a son who was white. The father seized the son and came to Rebbe and said to him, “Perhaps this is not my son.” Rebbe replied, “Do you have portraits in your house?” He said, “Yes.” “Are they black or white?” [Rebbe asked.] “They are white,” [he replied.] “It is from this that you have a white son,” [Rebbe responded to him.]
Although this science has now been displaced by the science of genetics, its acceptance by Bereishit Rabbah and the Talmud need not bother us from a faith perspective. Regarding issues of science, Rambam writes that the Rabbis were no more advanced than the experts at their time, and did not always understand the science fully (Guide to the Perplexed, III:14). But what are we to make of the Torah’s story? Doesn’t the Torah implicitly recognize the validity of this false scientific belief? It does not. The Torah relates that Yaakov operated with this belief, but it does not tell us why, in fact, the flock gave birth to spotted and striped sheep. Indeed, the next statement in Bereishit Rabbah attributes these births to a different cause altogether:
Said Rav Huna of Beit Horon: Ministering Angels would carry sheep from Lavan’s flock and come and place them in Yaakov’s flock [at the time of copulation]. This is what is meant by the verse, “[And the angel said:] Lift up your eyes, and see – all the rams which leap upon the cattle are striped, speckled, and spotted.” (31:12)
According to Rav Huna, while Yaakov might have thought that his success was due to the striped sticks, it was really all God’s doing, and it was done by using a good old-fashioned science: mating the ewes with the right type of rams. This seems to be the pshat. The Torah presents us with two contrasting explanations for Yaakov’s success: the sticks and the mating with the rams. The first represents Yaakov’s efforts, the second, the actual truth which the angel reveals to Yaakov (“lift up your eyes and see…”). The moral here is one which runs through many of the Yaakov narratives: while Yaakov exerts great effort to achieve his goals, often by engaging in subterfuge, his success is not a result of these efforts but rather of God’s promised protection. This lesson is finally learned by Yaakov in next week’s parasha, when, faced with Esav’s approaching army, he abandons his plans and strategies and turns to God for help and salvation.
As far as the science of external influences is concerned, other rabbis, in addition to Rav Huna, rejected it as well. In Nedarim, Rabbi Yochanan (not to be confused with Yochanan ben Dahavai) dismisses the position of Yochanan ben Dahavai and his concerns regarding certain forms of marital sex. He states that no particular act of marital sex is forbidden or discouraged. In so doing, he rejects the notion that such acts impact fetal development and states that this belief, held by certain rabbis, is not actually true, nor is it relevant for matters of halakha.
Despite Rabbi Yochanan’s rejection of the position, the belief in this science does not fully disappear. A number of Rishonim state that a couple should still avoid some of the activities mentioned in the Talmud to “play it safe,” and protect against the possible impact that these activities might have on their child. In addition, in a different passage, the Gemara (Berakhot 20a) relates the following story about none other than Rabbi Yochanan himself:
Rabbi Yochanan used to go and sit by the gates of the mikveh. He said: When the daughters of Israel come up from immersing themselves, they look at me and they have children as handsome as I am.
This passage is shocking for a number of reasons. First, Rabbi Yochanan was not concerned that he would have improper sexual thoughts. Second, it indicates that it would be acceptable for a woman to be thinking of another man (here, Rabbi Yochanan) while having sex with her husband. Finally, as it relates to our topic, it appears that Rabbi Yochanan believed that one’s thoughts during sex could, in fact, impact the formation of the fetus. It is thus all the more significant that he rejects the halakhic implications that this would have for restricting certain acts of marital sex.
Possibly, Rabbi Yochanan distinguished between actions and thought. One’s actions do not influence the development of the fetus; one’s mental state and thoughts do. This conclusion is implicit in the final statement in the passage from Nedarim. The Talmud states that while there are no sexual acts that are off-limits, there are times when sex is forbidden because of the emotional and mental state of the participants. Specifically, the Talmud states that the couple may not have sex if the act is devoid of any sense of intimacy or connection. They may not engage in sex when one of them is drunk or asleep, in the absence of full consent, or while imagining having sex with a different person.
Here too, the Talmud connects this to the character of a child born from such a coupling: children conceived during such moments will turn out to be rebellious and sinful. Immoral acts during conception impact the moral character of the child. It is the moral character of the act which matters, not the particular physical activity engaged in. Through limiting this “science,” the Talmud moves from a focus on sexual acts to a focus on sexual ethics.
The story does not end there. Given that what really mattered was a person’s thoughts at the time of conception, a number of Rishonim, and in particular the Kabbalists, such as the author of Iggeret HaKodesh, directed the man to focus his thoughts on the Divine to ensure that the child would be wise and God-fearing. [The emphasis here and elsewhere on the man’s thoughts and role during sex in contrast to the woman’s is a topic for another time.] Some contemporary poskim push back on this and state that the purest thoughts that a person can have during sex is to be focused on his or her partner and the intimacy between them.
Yaakov’s attempt to breed sheep based on a belief in a particular science is a lesson in how human efforts can so often be misguided, and in the need to put one’s faith and trust in God. At the same time, The Talmud’s narrowing of the scope of this science, and the resultant conclusions for the marital life of a couple, demonstrate that our human efforts are best directed to partnering with God, to believing in the truth of God’s Torah and to interpreting and applying it so as to best shape our religious lives and values.