Rav Yahudah Henkin Shlit”a wrote in 1990 in response to a question of whether Jews should organize and participate in a demonstration for Russian Jews.
"And your question concerning a member of one of the American rabbinic organizations who publicized a prohibition against demonstrating (for the Jews of Russia) in the name of R’ Moshe Feinstein Z”L, as opposed to another organization of rabbis who supported the demonstration according to what R’ Yoseph Dov Soloveitchik told them at the time. In my humble opinion, since the idea of a demonstration is learned from the Gemarra (Rosh Hashanah 19a), and the only requirement is to ask, before any demonstration, whether any benefit will come from it or not, as I already wrote, therefore it is a matter of the situation at hand (לכן הוא ענין מציאות) and we do not base our thinking on what was said about seemingly similar matters ten years ago, for much has changed since then. All the more so, according to your words, that you asked R’ Moshe Feinstein Z’L in 1981 and he told you that it is not forbidden to demonstrate, and I also heard from his son-in-law that R’ Moshe wouldn’t forbid it today. And therefore, even thought these words are not enough to publicize a permissive ruling from him, it is also not relevant to publicize a prohibitive ruling from him. And also, that you asked the gaon R’ Yoseph Kaminetzky Z’L and, according to your words, he was opposed to demonstrations in the past according to his familiarity with Russia from years ago, but if matters have changed, then he now would not forbid it. And it is also known that the gaon, my grandfather and teacher (R’ Eliyahu Henkin) Z’TzL always opposed demonstrations, but he himself conveyed an argument that could be used against his own view, as he said that in matters of the situation at hand (עניני מציאות) it is impossible to base one’s thinking on the words of great Torah sages of pervious generations, because situations change and, if they were alive, perhaps they would say differently. And the truth is that great Torah sages know how to change their views, but less-great people do not have awareness and do not know how to change their minds, and they base themselves on opinions of great Torah sages for a time and place that they did not speak to, and many negative effects come out of this."
Rav Henkin in no way implies that R’ Soloveitchik knew more than R’ Moshe about demonstrations. He seems to assume that everyone offered the appropriate response given the situations at hand that they encountered.
But Rav Henkin is strong on the conviction that situations change, and that even the greatest gadol of one generation, when discussing questions pertaining not to halacha but to “the situation at hand” (עניני מציאות), cannot and should not be invoked as proof that one should act in one way or another when the situation at hand has changed.
What marks a gadol is not only one who knows enormous amounts of Torah but one who is able to attune to the specifics and nuances of a situation, and is able to change their thinking about certain categories of behavior based upon chaining times.
And a katan is someone who cannot do so, and therefore feels compelled to identify and hang on to words of a sage referring to a different situation and insist that those words apply also to this situation. Many negative effects come out of this.
If you look at the matrix of leadership here, you see there is the asker (who has also asked other people), there is Rav Henkin (the younger) and R’ Soloveitchik, and there are leaders of previous generations - R’ Moshe, R’ Kaniefsky, and R’ Henkin (the older).
R’ Henkin (the younger)’s role is to apply the principles of the older generation to the situation of the asker. He boldly asserts that the situations those previous leaders were referring to cannot be automatically brought to bear on the current question.
What is R’ Moshe’s position, then, or the senior Rav Henkin’s, in the matrix of leadership? How is he relevant to the demonstration? If he were alive, he may well have had the interest and capacity to speak to the question of whether or not the situation at hand called for a demonstration. And one would hope that, if he didn’t feel sufficiently familiar with the situation at hand, that he would desist from opining, and would instead work to convey the general principles of such decision-making to a leader who was more attuned to the situation at hand.
Rav Kook, on 4 Av 5668, wrote a letter in response to a previous letter from R’ Yitzhak Isaac Halevi. Their correspondence revolved around a favorite topic of Rav Kook’s - the yeshiva he planned to build in Yaffo, and the anticipated curriculum of that yeshiva. Rav Kook wrote as follows:
When I say that we need to learn the spiritual side of Torah in a consistent and serious way, and that the salvation of the generation is dependent on this, I do not at all plan to confine my plans to specific books, neither later nor earlier books. My intention is not to learn R’ Saadya Gaon’s Beliefs and Opinions, or the Guide for the Perplexed, or the Kuzari or the like, in and of themselves, in order to learn the opinions contained therein, such that those opinions would become weapons with which to fight our battles. I know that the time is past for most of the matters contained in these precious books. Many of them, in truth, have become null because their philosophical foundations have become null, and a substantial portion of those ideas, even though they really ought to be taught and learned, being that they are eternal ideas that cannot become null in the face of any shift of ideas, but the world is removed from this expanse of inquiry because they have abandoned all manner of spiritual thought, and they have chosen the wisdom of life and of action in its place.
Generations have different priorities. Realities change. Is it reasonable to assume that the same people can lead through different generations and different realities?