Amongst the heated debate that has been going on regarding get me'usa - more subtle issues have been ignored. We addressed the issue of whether we posken like the Rambam (Hilchos Ishus 14:8), that a husband can be forced to give a get in a case of ma'us alei or like Rabbeinu Tam, that force can't be used and if it is used you have a problem of mamzerim. While it is clear that we don't posken like Rambam - there are a number of unclear areas. For example what happens if the husband were forced to give a get and then his wife remarried? If the get was invalid she shouldn't be allowed to remarry and if she does - the marriage would not be valid and future children would be mamzerim. One of the sources that is cited in this question is the following Rosh.
Rosh(43:6): Question: A woman has been married for many year and has children. Now she is saying that he disgusts her (ma’us alei). Do we force the husband to give a get? Answer: Even though the Rambam writes, When the wife says ma’us alei we force the husband to give her a get – but Rabbeinu Tam and the Ri disagree. Since this is a dispute amongst rabbinic authorities why should we stick our heads amongst the great mountains and to make a forced get which is not required by the halacha and to permit a married woman to remarry? Furthermore due to our sins, Jewish women today have loose morality. Therefore there is concern that the wife might be interested in another man. Whoever forces a husband to give a get when the wife says ma’us alei is simply multiplying mamzerim. All of this is in regard to what to do if asked. However if the get has been forced already – if they relied on the view of the Rambam – what has been done has been done.
Question: What is the Rosh doing here in regards to deciding between the Rambam and Rabbeinu Tam?
Answer: In fact he isn't deciding between them and doesn't want to. It seems therefore he is following the assertion found in the introduction to Ohr LeTzion of Rav Bentzion Abba Shaul that psak is a not a clear categorization of what is true and what is false but rather it is a strategy to minimize error and harm. He says only in the case of the Shulchan Aruch because it was accepted by clall Yisroel and the Arizal because he spoke with ruach hakodesh - are their rulings absolute decisions of truth. While it seems clear that the Rosh is doing a cost benefits analysis - other poskim such as Rabbeinu Tam, Ramban Shulchan Aruch etc are clearly rejecting the Rambam and saying that he is wrong!
It would seem that in our time - after the Rambam has been rejected and Rabbeinu Tam accepted - that the ambivalent view of the Rosh would not be relevant. However it is cited by contemporary poskim such as Rav Ovadia Yosef to explain why the wife can remain married to her second husband - despite receiving an inappropriately forced get from the first.
An explanation might be that contemporary poskim are also doing a cost benefits analysis rather than deciding what is true. Thus they take the conservative approach of Rabbeinu Tam and don't allow the husband to be forced because they are worried about the possibility of mamzerim if Rambam is wrong. They would also say that a wife divorced by a forced get could not get married with that get.
However if she does get married we have a different problem. There is now a marriage and possibly children. Thus we would definitely have adultery and mamzerim if we had absolutely rejected the Rambam. Therefore we turn around and say - we didn't absolutely reject the Rambam but that he is not the normative lchatchila position. However when faced with the disaster of adultery and mamzerim we say the Rambam can be relied upon bedieved.
To get back to our problem of using force in ma'us alei. The guiding principle that we seem to be using is that we need to avoid the possibility of an invalid get and thus mamzerim if Rambam is wrong. Therefore all our actions need to be based on the rejection of the Rambam and thus we avoid any appearance of forcing the get. However if there is a forced get - then bedieved we would rely on the Rambam that there is no problem of aishis ish and mamzerim - because there is no other way.
Assuming that is really the halachic dynamic - what would be the practical status of children resulting from remarriage? If you had a choice between a possible zivug with a person for whom there was never a question of yichus versus one for whom the valid is solely because there was a pesak that bedieved the child is kosher - which would you chose? In other words which would you chose - glatt kosher in which there has never been a sofek or regular kosher which had a number of questions that were resolved by a rabbi's heter that took 10 pages of reasoning to justify and that other rabbis don't accept?
This issue of perceived quality of yichus is also a consideration - at least l'chatchila - in how we conduct ourselves. In other words we should avoid doing anything which raises halachic questions of yichus - unless there are other issues which are more important.
In addition there are contemporary poskim who view the Rambam has rejected totally and they problably would require that the wife not only not remarry after a forced get but that if she did then she could not stay in the marriage and that children from the second marriage would be mamzerim.