Disagreeing with Gedolim

 Igros Moshe (O.C. 01:109): This that you apologize for disagreeing with me in a halachic issue – this is totally unnecessary. That is because this is the way of Torah that it is necessary to establish the truth. Chas v’shalom to silence one who disagrees with you – whether he is being more lenient or more strict. [While there is a discussion about disagreeing in a formal court session Sanhedrin 36 where the court is deciding on the guilt or innocence…] it is not a problem to disagree with the gadol (greatest scholar) when he is saying something in the course of teaching the material or even if he is making a practical halachic ruling but he is not part of a formal court. We see this in many places in the gemora where students question their teacher’s view. … It is obvious in these cases the rulings were not part of a formal court session. Furthermore it is apparent that there is no one today who has the status of gadol for this law that no one can disagree with him… Therefore even if you consider me to be a gadol – it is permitted to disagree with me and consequently it is required that you express your opinion and there is no need to apologize. Nevertheless regarding the halachic question that was raised, my view -that I wrote that it is prohibited - is the correct one.

Igros Moshe (Y.D. 01:101): .... 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 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 woman 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.