Sometimes understanding the whole picture forces a posek to radically reimagine how a Halachic concept will be applied. Rarely have I seen a posek who did this more masterfully than Rabbi Shlomo Zalman Aurbach and his understanding of lifnei iver with non-religious Jews. The shiur and sources are available here.
The Gemara (Chullin 107b) rules that one cannot give food to a waiter unless he knows that the waiter will wash his hands first. Rabbenu Yonah (Brachot Perek Eilu Devarim) extends this to forbidding giving food to someone who won’t make a bracha, a position accepted lehalacha (Shulchan Aruch Orach Chaim 163, 169). This is based on lifnei iver. There is some discussion amoung the poskim as to whether this applies only when he will definitely not wash or make a bracha or even by safek, whether this also applies when by giving food one is mekayem a mitzvah (such as tzedakah), what happens if the person can get the food by himself, etc. We will not get into details here.
Rabbi Shlomo Zalman (Minchat Shlomo 1:35), however, notes that there is a complicating factor that is especially pronounced in modern times. Especially with the existence of multiple denominations, there are many people are truly love and support Torah, but are not themselves shomer Torah u-Mitzvot. These people, if they are embraced for who they are by religious Jews, will continue to love Torah and perhaps come closer to it. If, however, they feel rejected, they will be driven away. If religious Jews refuse to give them food when they visit because they won’t make a bracha, they will often become spiteful of Torah and those who keep it.
In a simple and elegant teshuvah, Rabbi Shlomo Zalman takes these factors and turns the sugya on its head. In theory, he could have argued that we can permit giving food as this is a shaat hadechak, it will cause a chillul Hashem, etc. Instead, he argues that lifnei iver must take the entire picture into account. As the very nature of the prohibition is cause others to do something harmful for themselves, we have to ask whether the facts on the ground change what is better for the people involved. He argues that nowadays, if we were to worry about him making a bracha, we are risking him violating the much greater prohibition of hating Torah and those who represent it. We are driving him away and making it more difficult for him to come closer to Torah. Thus, not only are we not prohibited from giving him food because of lifnei iver, we are obligated to give him food because of the same legal principle. The legal analysis and boldness, coupled with the astute understanding of the reality he is dealing with make this teshuvah an absolute masterpiece. Mori VeRabi Rabbi Mordechai Willig has told me without hesitation we rule like this teshuvah, and Mori VeRabi Rabbi Yehuda Amital zatzal writes similarly in his sefer Risisei Tal.
As a contrast to this teshuvah, I presented Rabbi Moshe Feinstein’s teshuvah about inviting non-religious Jews to shul when they may drive (Igrot Moshe Orach Chaim 1:99). I assume the questioner wanted to draw these Jews close to Torah by bringing them into a Torah atmosphere, but wondered whether there were technical halachic problems. I assume he did not expect Rabbi Feinstein fire and brimstone response. Instead of sympathizing, he argues that this is not only a violating of lifnei iver, but of mesit – perhaps the single worst sin in the Torah. Mesit in its classical form is the prohibition against enticing others to worship idols. Not only does it carry the death penalty, but unlike other cases in Jewish law where we try to avoid executing the penalty, we look for ways of destroying the mesit. We are forbidden from showing mercy. Rabbi Feinstein argues that inviting someone who will drive to shul, while it does not incur the death penalty, in every other way is legally equivalent to mesit. In other words, this rabbi, who wanted to draw people close would be guilty of the worst crime of driving people away.
At first, this teshuvah seems incomprehensible, and in fact has been rejected by many poskim (ranging from the Dati Leumi organization Beit Hillel to the former Rosh Av Beit Din of the Edah Charedit, Rabbi Moshe Shternbuch). However, it seems likely that this teshuvah, was affected by another responsum written a few years before it. This teshuvah was written in 1953. In 1950, the first teshuvah emerged from the Conservative Movement permitting driving to shul on Shabbos. This teshuvah was presented in similar terms as the questioner in Rabbi Feinstein’s teshuvah – as an attempt to do “kiruv.” The Conservative Movement realized that many people were not as committed as they needed to be, and they tried to come up with many ways to bring them back. Among them, was to bring them back to shul at all costs, believing that this exposure would draw them closer to Torah. I would conjecture that whether or not Rabbi Feinstein read this teshuvah, he knew that there were people who were on principle choosing to erase parts of hilchot Shabbat in the name of “kiruv.” Under such circumstances, it is understandable to respond with drastic measures.
If one reads about the history of this period in America (see for example much of the wonderful work from Professor Jeffery Gurock, especially From Fluidity to Rigidity), one will see that one of the strategies that Orthodoxy chose to survive was to value principle over popularity. Instead of looking for leniencies, it decided to define itself and hold strongly to its principles, come what may. While Orthodoxy did lose many people during this period, in the long run, this seems to have saved Orthodoxy, which is now gaining strength, while other movements lose.
Many in the Conservative Movement have bemoaned the Driving Teshuvah, as it allowed (legally) the situation that led to the disintegration of community created by the need to walk to shul. In Israel, this position has even been reversed by Rabbi David Golinkin. There is recognition that sometimes extending leniencies is not just a bad decision legally, but sociologically as well.
I don’t know whether Rabbi Feinstein would have changed his position now, and I do not claim that he did not mean what he said halachically (how would I know?), but I do think that the fire and brimstone was caused by a recognition of the dangers that lurked in the Jewish community. The conjunction of Rabbi Feinstein’s teshuvah with the Driving Teshuvah should give us insight to how poskim must respond to the needs of their time and understanding that general atmosphere in which they poskan (obviously within the bounds of what they think is true or at least plausible in the sources), whether this leads to kula or chumra.