Q&A: An Archaic Medical Concern in the Sages
An Archaic Medical Concern in the Sages
Question
With God’s help,
Hi.
A small question:
In the Taz, section 195, subsection 7, he cites from the glosses to the old Semak: “A menstruating woman may lie on her husband’s sheets, but they are careful about sheets on which another man slept, lest she become pregnant from another man’s semen.”
I wanted to ask about this:
A. Does the Rabbi know whether this concern exists according to current medical knowledge? Is it possible to become pregnant through contact with semen outside the vagina?
B. Assuming this concern does not exist (that is, assuming those who were careful were mistaken), is there still some halakhic validity to this ruling? Because it could be that once certain glosses were accepted in Jewish law, even if their basis was mistaken, they still retain some validity (although I do not understand why).
If the Rabbi thinks there is no validity, but knows of those who consciously think there is validity, I would be happy to get a reference.
And while we’re on the subject, I would also ask whether one can become pregnant from semen in a bathhouse (which the halakhic decisors discussed in Even HaEzer section 1, whether such a child would count as a mamzer, and they arrived at such a case from the aggadic story about the conception of Ben Sira), according to current medical knowledge.
Thank you very much,
and may you be inscribed and sealed for a good year.
Answer
Hello,
First, I very much prefer questions through the site and not by email.
A. I don’t know, and I assume that this concern, even if it exists, is extremely remote and there is no reason at all to worry about it.
B. Why assume that the reasoning of the Semag is binding on someone who thinks it is factually incorrect? In the case of the Talmud or a ruling of the Sanhedrin there may perhaps be room for that idea (though I disagree even there), because they have authority. But where does the Semag get such authority? An erroneous custom should be abolished, all the more so here, where this is not even a custom but a concern (see my second column).
Many think it does have validity. Search online for discussions about the permissibility of killing lice on the Sabbath. Also see the book by Neria Gutel, The Changing of Nature in Jewish Law. Some hold that the Talmud does not err, and if science thinks otherwise, then science is wrong. Others say this is like a Jewish law whose rationale has lapsed, which does not change except by formal vote and count (= in the Sanhedrin).
I don’t know. I assume that even if it is possible, it is very rare.