Rabbi Hershel Schachter
The Talmud, as well as later rabbinical literature, is replete with halachic disputes. The halacha has had to decide which opinion should be followed. Should we assume that the rejected view was mistaken and simply incorrect? The Gemara (Eruvin 13b) states regarding the many disputes between Beis Shamai and Beis Hillel that, "eilu v'eilu divrei Elokim Chaim - both opinions are the words of the Living G-d." although in the overwhelming majority of cases we have not accepted the views of Beis Shamai, this does not mean that they were wrong; one who spends time learning the views of Beis Shamai is in fulfillment of the mitzvah of Talmud Torah. Beis Shamai were also basing their opinions on middos she'ha'Torah nidreshes bohein; they were following the principles and the rules of the Torah She'b'al Peh, just that they came to a different conclusion than Beis Hillel. Therefore learning their opinions would also constitute a proper fulfillment of the mitzvah of Talmud Torah. To use the terminology of Rav Soloveitchik, their views also constitute a cheftza shel Torah.
The Ritva (ibid) explains as follows: when Moshe Rabbeinu was on Har Sinai and received the Torah from Hashem, he asked the Ribbono Shel Olam what the din would be in various cases, and in some Hashem told him the din is assur, in some He told Moshe muttar, and in some Hashem told him that the case had elements of issur and elements of hetter and He leaves the matter up to the Torah scholars of each generation to determine whether - according to their perspective - the elements of issur outweigh the elements of hetter, or the reverse; and since different people can each have different perspectives even though they are looking at the same thing, more than one can be correct. This is the meaning of the idea that, "eilu v'eilu divrei Elokim Chaim."
This concept does not always apply in all cases. Rashi and Tosafos (Kesubos 57a) point out that sometimes we must assume that one of the opinions is clearly incorrect. Sometimes we see a dispute among the later rabbinic authorities where one of the opinions simply overlooked a passage in the Talmud, or sometimes even an explicit passuk in the Chumash. In such a case we clearly will not apply the idea of eilu v'eilu.
Even when we do apply "eilu v'eilu divrei Elokim Chaim" it does not mean that halacha l'ma'aseh one has the right to follow whichever opinion he wishes. The original statement in the gemara regarding eilu v'eilu was with respect to the many disputes between Beis Shamai and Beis Hillel and nonetheless the gemara (Berachos 36b) states that, "Beis Shamai b'makom Beis Hille eina Mishna", i.e. we totally ignore the opinions of Beis Shamai with respect to psak Halacha, and unlike other minority views that were also not accepted, we don't even consider the views of Beis Shamai as creating even the slightest safeik (safeik kol-d'hu.) Regarding Hilchos Aveilus and Orla b'chutz la'aretzm, even when dealing with a d'oraysa issue, the halacha says that in the presence of any slight safeik we go l'hakeil, even if the probability of the doubt is nowhere near 50%. A minority opinion which was not accepted constitutes a slight safeik. But because the views of Beis Shamai were outvoted by Beis Hillel when they met together and debated their issues, their opinions are totally ignored halacha l'ma'aseh. (See my sefer, B'Ikvei Hatzon, siman 38, for more on this topic.)
Likewise the poskim assume that when you have a shitah y'chida'ah, a lone opinion among poskim not shared by others, this view also does not constitute a slight safeik. The Beis Shmuel (Rema, Shulchan Aruch Even HoEzer siman 90, s'if kattan 6) thinks that even if the Rambam agrees with the Ri Migash on a position not agreed upon by other poskim, this view should be totally ignored, since the Rambam was so taken by the genius of the Ri Migash (his father's rebbe), and would naturally be inclined to accept his opinion without even thinking twice (even though in several instances the Rambam does reject his opinion), this psak would be considered a shitah y'chida'ah and should be totally ignored.
It was recently reported that a certain "beis din" permitted a married woman to remarry without a get, because it was ascertained that her husband was not Sabbath observant at the time he married her, and the halacha considers one who is mechalel Shabbos b'farhesia to be like a non-Jew. And, they reasoned, we all know that if a non-Jew marries a Jewish woman the marriage does not take effect. This ruling is absolutely scandalous. First of all, the consensus of recent poskim has been that the concept of mechalel Shabbos b'farhesia doesn't apply today since so many Jews are not shomer Shabbos and the term "b'farhesia" has the connotation that this individual is breaking the discipline in the community (Chazon Ish and Binyan Tzion.) The members of this "beis din" would most certainly have been the first to say that such a Jew would not cause wine he touched to become prohibited because he is not considered to be like a non-Jew. More importantly, the view that a Jew who is treated as a non-Jew because he is mechalel Shabbos b'farhesia can't effectively marry a Jewish woman is totally ignored, because it is against an explicit gemara (Yevamos 47b) that states that even if a Jew converts to another religion and marries a Jewish woman the marriage does in fact take effect. We can't apply the concept of eilu v'eilu to this view; it is simply incorrect.
Even in an instance where we do apply eilu v'eilu, for example regarding the views of Beis Shamai, one may not follow their opinion. Eilu v'eilu means that one who spends time delving into the understanding of the views of Beis Shamai is fulfilling the mitzvah of Talmud Torah, but it does not mean that it has ramifications halacha l'ma'aseh.
There are rules and regulations regarding psak halacha; this discipline is not hefker (is not a free for all.) The parsha tells us that the halachic positions of the Beis Din Hagadol are binding on all Jews. The Sanhedrin was a group of Torah scholars who were clearly head and shoulders above all of their contemporaries. They were the gedolei hador (the Torah giants of their generation), and the gedolei hador have the status of rabo muvhak for their entire generation, even for those who never even met them (see Tosafos on Berachos 31b and Shulchan Aruch, Yoreh Deah 244:10.) The halachic positions of one's rebbe muvhak are binding on him, and the halachic views of the gedolei hador (who are clearly head and shoulders above the other Torah scholars of their generation) may not be ignored. None of the members of the aforementioned "beis din" are recognized by anyone as belonging to the category of gedolei hador, and even if it had been a case where we would apply eilu v'eilu, since the gedolei hador have unanimously rejected it for generations, no one today who is not in the category of gedolei hador has the right to go against this rejection!
Rabbinic leaders throughout the generations are always concerned with the plight of agunos, but coming up with non-halachic solutions is not the Orthodox way. The Talmud Yerushalmi seems to hold that the concept of pikuach nefesh doesn't only apply when one's life is in danger, but also if one's life will be made extremely miserable this too falls under the category of pikuach nefesh, which allows one to violate Torah laws. The Yerushalmi (quoted by Rav Yosef Engle in Teshuvas Aguna) says that we would have allowed every agunah to violate the prohibition of adultery if not for the fact that we are dealing with gilui arayos (forbidden marriages) where the halacha does not permit one to violate the mitzvah even in a case of literal pikuach nefesh - even to save one's life.
The aforementioned "beis din" is doing a disservice to the Orthodox Jewish community at large, and specifically to these poor agunos, by misleading them with absolutely scandalously fallacious piskei halacha. Let the public beware! One must be of the caliber of Rav Chaim Ozer Grodzinski in his generation or Rav Moshe Feinstein in the past generation in order to determine in a given case if the halacha permits a woman to get remarried without a get.
Postscript: regarding the aforementioned "beis din", also see Important letter from Rav Hershel Schachter, Rav Gedalia Dov Schwartz, Rav Nota Greenblatt, Rav Avrohom Union, and Rav Menachem Mendel Senderovitz regarding the "International Beit Din".