Thought for the Day: Surrogate Motherhood -- Argument That It Is Impossible to Determine Whether Birth Or Genetic Mother is Halachic Mother
On the issue of who is the halachic mother in the case of surrogate motherhood, we have seen an argument for the genetic mother and an argument for the birth mother. Both had proponents, but neither had the universal acceptance. (Ok... almost nothing this complex has universal acceptance, but neither has even enough acceptance to definitively declare, "This is the halacha.") There is one more argument, that it is impossible to make such a determination. (Spoiler alert: this argument will suffer the same fate as the other two; we'll deal with that shortly.)
For those of you who do not live in Chicago or Eretz Yisrael: let's review the relevant halachos of חדש (new grain) and ישן (older grain). The Torah forbids the use of new grain until after הקרבת העומר/the Omer offering is brought, which is on the second day of Pesach -- 16 Nissan. When we have the בית המקדש, then חדש grain changes status to ישן with הקרבת העומר; nowadays, we wait till 17 Nissan. You may be wondering... no, you should be wondering (unless this is all old had for you, in which case you can skip to the next paragraph) what criteria determine whether the grain is from this year's or last year's crop. Great question! The answer is: grain that took root and grew at least a third before הקרבת העומר is from last year's crop, otherwise it is from this year's.
At this point you most definitely should be wondering what in the world this has to do with surrogate motherhood. Your wait is over: Chazal address the situation of grain that has grown more than a third before הקרבת העומר (ie, it is ישן), then was uprooted and replanted (:מנחות צ'ט). Regarding the new growth, ask Chazal, do we consider it to be an extension of the old growth and so it is ישן, or is it considered completely new growth and is therefore חדש? Tada! That's precisely our question: do we look at the new growth (the fetus) as a continuation of the original growth of the ova, or is it considered now as a growth from the uterus of the new (surrogate) mother.
Drum roll please... the answer is: תיקו... question cannot be resolved; let it stand; maybe Eliyahu will be able to clarify it for us, or not. Anyway, even if we did know how this works out, R' Shlomo Zalman Auerbach was not so excited about a proof regarding humans from plant growth. I don't know what he didn't like, but it is certainly understandable as the mechanism of adding more plant growth is nothing at like the creation/growth of the embryo in a human.
Bottom like, we started with four possibilities (none, both, genetic, birth) and have concluded it is either the birth or genetic mother, but there is no universally accepted proof of which, and we even have one argument that it is unknowable (to us). That means the kid will not be able to marry any of either mother's relatives, but he will also not be able to inherit from either mother.
It's times like this that I appreciate having no halachic relatives; much simpler!