Former Harvard University law professor and civil rights activist Derrick Bell died Oct. 5 from carcinoid cancer. He was 80.

“From his work on the front-lines of legal argument in the civil rights movement to his pathbreaking teaching and scholarship on civil rights and racial justice issues, Professor Derrick Bell inspired and challenged generations of colleagues and students with imagination, passion, and courage,” Harvard Law School Dean Martha Minow said in a statement.

In 1971, Bell became the first tenured Black professor at Harvard Law School, leaving in 1980 to serve as dean of the University of Oregon School of Law. He resigned from that position after the school denied tenure to an Asian woman.

Bell returned to Harvard in 1986, but left in protest of that school’s hiring practices in 1990. He later became a visiting professor at NYU, where he worked until his death.

Bell championed critical race theory, which believes that racism is ingrained in laws and legal institutions, including those intended to reduce the problem. His theories were sometimes unpopular, among them his belief that the landmark school integration decision in Brown V. Board of Education may have done more harm to the education of Black children than good.

In addition to being a civil rights leader, Bell often spoke about ethics and how important it was to live a Godly life.

“We can’t wait for leaders,” he told NPR in 2002. “God is within us to a certain extent, you know, and we have to justify the miracle of our existence not by driving the E Class Mercedes — nothing wrong with that, but that should not be our goal. Our goal should be to justify our existence by loving God, by loving others.”

Bell is survived by his wife, Janet Dewart Bell, three sons, two sisters and a brother.