She was saying of Jewish law what many say of the Constitution: it must change with the times, it has, and it was designed to. So, for example, rabbis could find — and in the past, have found — legal justification to free women from failed marriages, even if their husbands do not consent. (In Orthodoxy, only men can enact a divorce, so in contested divorces husbands can extort money, or favorable custody arrangements.)

Her view of Halakha “was a lightning rod for her critics,” said Marc D. Angel, an Orthodox rabbi and longtime friend. In his view, “her real greatness will be more fully appreciated in coming generations.” Even if “one can quibble with this point or that,” Rabbi Angel said, “she has been a phenomenal personality within Orthodoxy: courageous, articulate, and clear-thinking.”

Many Orthodox “like to behave as if the Halakha were completely objective,” said Rachel Adler, a Reform rabbi who teaches at Hebrew Union College in Los Angeles. “Blu was pointing out that anybody who reasons Halakhically has an investment in how it comes out, and that rabbis were responsible for how the Halakha that they wielded treated women.”

Ms. Greenberg admits that she gets a respectful hearing in part because of her yikhes — lineage, family stature. Her husband, Irving, an Orthodox rabbi, founded the Jewish studies department at City College of New York. She seems to know everybody. Did Shmuel Goldin, the past president of the Rabbinical Council of America, word his criticism so carefully — “Her famous statement where there’s a rabbinic will, there’s a halakhic way, we consider to be simplistic and populist in nature” — in part because his mother was once Ms. Greenberg’s baby sitter?

Ms. Greenberg is careful to state, and restate, her commitment to Orthodoxy. She wrote a classic homemaker’s guide, “How to Run a Traditional Jewish Household.” And in her early writing, she could be very critical of secular feminism, as if trying to protect Orthodoxy from it. “Feminism,” Ms. Greenberg told me, “had a — I can’t say anti-family, it was so long ago that those words sound very harsh — but it had less tolerance for some of the constructs in Orthodoxy that were perfectly in order as far as I was concerned.”

Being Jewish and a feminist does not mean, for Ms. Greenberg, that the two identities are of equal importance. “My priority is my community, my people,” Ms. Greenberg told an audience at Harvard Divinity School, in 2002. “I see much less danger in whether the rights to abortion will be withdrawn than I do to Israel’s viability or to anti-Semitism, the specter of anti-Semitism that is rising in the world and how that will impact on my children and grandchildren.”

I was there, and I remember the gasps. Jewish survival more important than abortion-rights politics? Her audience was shocked. But no matter. “I have always found it’s better to plunge in with whatever you think is the truth and don’t think about politics,” Ms. Greenberg said. “You may have to pick up the pieces afterward.”