In an Orwellian era when the president’s personal lawyer says that “truth isn’t truth” and when lies are excused as “alternative facts,” a newly released documentary film provides a potent reminder of one public official who wasn’t afraid to speak his mind without perverting reality.

The film, titled “Moynihan,” profiles Daniel Patrick Moynihan, the flamboyant, technocratic, political-clubhouse-bred and Harvard-honed four-term United States Senator from New York, United Nations ambassador and adviser to Presidents John Kennedy, Lyndon Johnson and Richard Nixon. Produced by Joseph Dorman and Toby Perl Freilich, the documentary is being screened this month in New York, Los Angeles and Washington.

Moynihan, who died in 2003, famously said that people are entitled to their own opinions but not to their own facts. He also liked to quote the maxim that “it’s not ignorance that hurts so much as knowing all those things that ain’t so.” Which can only make you wonder how much he, as that rare commingling of politician and public intellectual, would be wincing at the categorical claims coming from Congress and the White House nowadays.

Moynihan distinguished himself because he derived his policy positions from research, rather than by cherry-picking statistics to justify those policies. That’s how he propelled himself to the forefront of issues like auto safety and climate change, as well as the question of the durability of the Soviet Union. He championed equal rights and recognition for women, including his wife, Liz, whom he valued as an equal partner in a male dominated town.