Marilyn Frye is a professor of philosophy at Michigan State University, and is a leading scholar in the field of feminist philosophy. Her essay, Oppression, has been extremely influential and her book The Politics of Reality: Essays in Feminist Theory is widely read. I'm not really a theory person, but she has a writing style that seems to miraculously clarify muddy issues. She isn't the same person as Marilyn French, with whom I had her confused for years.