I was born in 1989. In my lifetime — in just my 14 years of adulthood — I’ve seen dramatic changes in public attitudes toward the LGBTQIA+ community. That acronym alone has gained greater inclusion and meaning. When I turned 18, it was still common for mainstream American news to question the nature of homosexuality and queerness — for both sides of the aisle to oppose same-sex marriage as a right, for instance. (It seems Congress may soon answer that question in the affirmative.) That doesn’t mean American hearts are fixed, much less those around the world, but sometimes it’s worth thinking about how far we’ve come. Amid the constant drumbeat of bad news, it’s OK to take stock, and heart, of success.

Of course, I mention my age because I’m still relatively young in the world of American political experience, and there are many younger than I am who haven’t necessarily felt a sense of progress during their public lives.

That’s where documentaries like Not a Tame Lion become important. The film from director Craig Bettendorf is a biographical mosaic of scholar John Boswell, a medieval philologist whose expertise in reading historical texts led him to a career studying the role of homosexuality in ancient religion, particularly Catholicism. Boswell’s work was most widely read in the 1980s and 1990s, with Christianity, Social Tolerance, and Homosexuality and Same-Sex Unions in Pre-Modern Europe among his work. Boswell played a role in disputing assertions by the then-ascendant Christian Right about homosexuality as a sin. A devout Christian himself, Boswell’s intense focus on finding legitimacy within Catholic history was unique among gay and lesbian scholars at the time, and feels far removed from where we are today. He sought to change the Church and its beliefs from within through thorough study.

Battendorf’s film dives into Boswell’s study, comparing the writer to the character Robert Langdon from The Da Vinci Code — diving into primary sources to find secret truths the papal powers-that-be wanted to keep hidden. Some of the stories about Boswell’s experiences aren’t too far off. Once Christianity won the National Book Award in 1981, the Vatican became aware of Boswell’s writing and made it as difficult as possible for him and his assistants to access archival material. In the most entertaining part of Bettendorf’s story, old friends and research partners fondly recall the way Boswell circumvented obstacles placed in the path of his research.

Rightly, though, Not a Tame Lion spends much of its time exploring Boswell’s life through the eyes of close friends and family, trying to uncover the life that made him such a trailblazing figure at the time. He lived as an out gay man at a time when that was tremendously difficult. He maintained deep faith in a religion that didn’t seem to want him. He made theological and historical arguments that to this day are controversial even within their own LGBTQIA+ sub-fields. Some argue that his work has since grown irrelevant or been discredited by later scholarship, but it has a historical importance and speaks to the time and prevailing attitudes of its origin. It’s worth holding onto and revisiting, and doubly worth understanding the man who wrote it and why.

Boswell died of AIDS-related complications in 1994, prior to the publication of Same-Sex Unions, and left quite a legacy. As the world continues to grow and change, it’s easy to lose sight of those who blazed their own paths in seeking legitimacy for the LGBTQIA+ community. Boswell’s is a story worth remembering, and Bettendorf’s documentary takes a thoughtful look at a monumental life.