Roughly two years into the making of this searing and unforgettable doc, Mayer Vishner announced that he was preparing to end his life.

“I’m dying of lonliness,” pleads the aging Yippie, a man whose influence on American radical culture is incalculable, but who feels—alcoholism and clinical depression aside—that his time is up. His arguments are cogent, his trickster wit intact, his friends resigned. Filmmaker Justin Schein’s treatment of his own subsequent ethical dilemma is sometimes a litte too on-the-nose, but the viewer is haunted by subtler questions raised by Left on Purpose.

From Vishner’s super high-functioning youth to dereliction in one lifetime—how’d that happen? Why is suicide seemingly epidemic among his old colleagues? And what place is there now for a committed American dissident who didn’t sell out like Jerry Rubin or check out like Abbie Hoffman?