Mary Daly, a controversial lesbian feminist theologian, author, and longtime professor at Boston College, died Sunday at age 81. She had been in poor health for two years.

Daly, brought up Catholic, once considered herself a worker for reform in the church, but early in her career she became a “radical, post-Christian” feminist, according to SheWired.com. As her obituary in the National Catholic Reporter put it: “Eventually, in her life and scholarship she developed a sweeping analysis of ‘patriarchy’ as the root of women's oppression and of all social ills in which people are treated as objects.”

She began teaching at Boston College, a Catholic institution, in 1966, when the student body was still all male. She was fired after the publication of her first book, 1968’s The Church and the Second Sex, but support from students and the general public led to her rehiring. She remained at the college, which eventually became coeducational, until 1999, and drew criticism for reserving some classes for female students only. In 1999 a male student was denied admission to one of Daly’s classes because he had not taken the prerequisite course. He sued and she was fired again. A countersuit by Daly supporters sought an injunction against her firing, and a settlement was reached in 2001.

Daly, whose other books include Gyn/Ecology: The Metaethics of Radical Feminism and Pure Lust: Elemental Feminist Philosophy, was remembered by colleagues as one of her generation’s most important feminist thinkers. “Her contributions to feminist theology, philosophy, and theory were many, unique, and if I may say so, world-changing,” wrote Mary E. Hunt, cofounder and codirector of the Women's Alliance for Theology, Ethics, and Ritual, in announcing Daly’s death.

Daly once wrote, “There are and will be those who think I have gone overboard. Let them rest assured that this assessment is correct, probably beyond their wildest imagination, and that I will continue to do so.”