R. Moshe Feinstein stood as a bulwark against innovations of liberal movements, delineating the borders between acceptable and unacceptable halakhic practice. His opposition to Bat Mitzva ceremonies is an iconic case in point. In this installment of "Unpacking the Iggerot," Moshe Kurtz shows us that behind this social issue lies a fascinating debate about the nature of how R. Feinstein chose what and when he wanted the public to read from his literature.

How far does one need to go to fast on Yom Kippur? R. Moshe Feinstein was asked not how to be exempted from fasting, but how can we make ourselves obligated? Moshe Kurtz takes us on a tour of several responsa with relevance for the upcoming holidays and demonstrates R. Feinstein’s broader approach to the role of artificial intervention in the halakhic process and a life motivated by joy of mitzvot.

Previously in "Unpacking the Iggerot" we reviewed R. Moshe Feinstein’s unequivocal objection to Kohanim attending medical school. This time around, Moshe Kurtz explores how R. Feinstein instead offers a novel leniency to enable Kohanim to fly to Israel…despite the halakhic challenges lurking beneath.

When a mysterious document purporting to permit kohanim to attend medical school surfaces, controversy ensues—involving the likes of R. Shimon Schwab, R. Shlomo Goren, and, of course, R. Moshe Feinstein. In this week’s “Unpacking the Iggerot,” Moshe Kurtz takes us through a fascinating episode in contemporary halakha that has the potential to imperil the ambitions of many Jewish mothers who would like nothing more than say, “My son, Dr. Cohen”!