Disagree wit5h Rishonim

 Igros Moshe (Y.D. 3:101): You ask how is it permitted to rely on these type of innovations such as  I have explained in actual rulings – and in particular since it is against certain Achronim? In answer let me ask whether an end and limit to Torah has been made, G d forbid!, so that we only make rulings in that which is already in books and thus when we come across questions which are not answered in the books we are unable to decide them even though we know how to do so? There is no question that is prohibited say such a thing. It is certain that the Torah can still develop and expand even now in our time. And we are obligated to do what we are capable of to decide every halacha that we encounter according to what is possible after investigation and serious analysis in the Talmud and poskim with clear thinking and proper proofs – even though it is a new halacha that is not mentioned before in the halacha books. And even regarding an issue that is discussed in halacha books – it is still necessary for the posek to understand it and decide the correct position prior to making a ruling. He should not make a ruling because that is what is says in a book – that is the similar to teaching out of the Mishna that the gemora says that the Tannaim who make mechanical rulings from codes of laws destroy the world (Sotah 22a). Look carefully at that gemora and Rashi’s comments. And even if the ruling goes occasionally goes against certain great Achronim – so what! There is no question that we have the right even to disagree with Achronim and also on occasion with certain Rishonim when there are proper proofs and more important with proper reasoning. Concerning this and similar matters the gemora says that a judge can only make a decision based upon what he sees (Bava Basra 131, Rashbam). This is true as long as the ruling doesn’t go against the well-known poskim such as the Shulchan Aruch which has been accepted in all countries. This is what is meant by the saying that there was a place left to make a fence. And this is in fact what the majority of teshuvos of the Achronim do – they decide many practical issues on the basis of innovations. However it is important not to be arrogant in making rulings. Thus one should avoid using innovations when possible except in situations of great need and surely in situations involving aguna such as the case under discussion. Thus we are obligated to make a ruling even if it appears to us that there is a basis for a heter. It is prohibited for us to show false modesty and cause a Jewish women to be trapped as an aguna or to cause a stumbling block with prohibitions or even to cause loss of money. Look at Gittin (56) where it condemns the humility of R Zechariah for causing the destruction of the Temple! The obvious question is what does humility have to do with the destruction? Look at Maharetz Chajes who gives a proper explanation. This is exactly what we are concerned about. Thus we must make halachic rulings according to what appears correct with proper proofs and understanding – and in particular in cases of aguna like this – to save from this difficult situation.

Igros Moshe (O.C. 5:24.6):… The Gra disputed even in those matters which were the basic customs of the Sephardim, French or Ashkenazim. It was agreed by the scholars of his generation that he was greater than the other sages of his generation who themselves were very great Torah scholars. In fact they agreed that he would have been one of the greatest scholars even many generations earlier and thus he had the right to dispute with the gedolim of many generations earlier. All of his students who were gedolim in that generation agreed that the Gra was able to dissent as if he were one of the Rishonim. And furthermore that since he was the latest such authority he was the final word and therefore his rulings were to be accepted. Gradually they began to follow his rulings in all matters even when it was against the established practice.

Yam Shel Shlomo (Yevamos 12:7): The Rosh (Sanhedrin 4:6) has written if the words of the early authorities are not convincing and you have support for your position it is possible to disagree with them – even with the Gaonim…

Shach (Yoreh Deah 242:8 Kuntres Hora’ah): In all cases where the words of the earlier authorities are written in a book and they are widely known and the later poskim disagree with their views – we accept the views of the later authorities. However occasionally we find a ruling of one of the Geonim – but it was never published in a book and we find his view is disputed – it is not necessary to rule in accord with the recent authorities because it is possible that they didn’t know the words of the Geon. And if they learned of it, it is possible that they would retract their views in favor of his. There are others who insist that we do not follow later authorities against the great early scholars. And therefore we should be strict. However if the later authority cites the words of the early authority and he still disagrees with him and it is well established that this later authority is qualified to disagree – then we can rely on the view of the later authority and it is necessary to reconcile the matter. Nevertheless if the posek has the freedom to decide, he is able to rule according to whichever view he wants. Nevertheless we are not to disagree with the early Geonim. Prior to the Rif, the generation of the Geonim ended. 

Chazon Ish (Shalom Yehudah):… I took it upon myself to research and examine the words of the gemora and commentaries as much as possible – even if the conclusions were against the Rishonim. While we need to accept that the words of our Rabbis are the essence and we are simply orphans of orphans, nevertheless that doesn’t prevent clarify, explaining and making sense according to what we are capable of despite our lowly status. Even making halachic rulings is permitted as long as it is in areas where there is no explicit accepted halachos which say the opposite. Because if I don’t do this I am lacking in my involvement with Torah. However this approach is only applicable to me, but it is obvious that others who aren’t attached to my words - their obligation is to choose the words of the Rishonim which are primary.