‘Doc,” which opens today at the Film Forum, is the latest in a series of documentary films, including Aiyana Elliott’s marvelous “The Ballad of Rambling Jack” and Mark Wexler’s “Tell Them Who You Are,” made about an esteemed and estranged relative by one of the subject’s offspring. It is also one of the very best. Like Ms. Elliott’s film, “Doc,” directed with tight but understated control by Immy Humes, is at once a life-and-times chronicle of its subject and a journey to a greater understanding and acceptance of circumstances and personal history that recast a father-daughter relationship as something more akin to fandom.

Born in 1926, Harold L. “Doc” Humes was a man of such varied interests — with an impatient need to directly apply them — that even cataloging his life accomplishments is no mean feat. A founder of the ‘Paris Review,’ Humes, who succumbed to cancer in 1992, was the author of two enthusiastically received (and long out of print, until Random House re-issued them this month) novels — 1958’s “The Underground City” and 1959’s “Men Die.” A third book never materialized, though Ms. Humes uses the notes her father made for what was to be a highly autobiographical follow-up to “Men Die” to great effect while retracing his steps from a death-scarred childhood to his years as a teen prodigy (and eventual dropout) at MIT.

Literary contemporaries George Plimpton and Norman Mailer reminisce about Humes’s years first in Paris and then in New York as a writer, editor, and bon-vivant in the 1950s and ’60s. Mailer is particularly eloquent about Humes’s larger-than-life personality and the ebbing and flowing sanity that went with it. Humes, Mailer admits, “was one of the few people I’ve met who was essentially at bottom more vain, more intellectually arrogant than I was at the time.”

Describing a moment that foreshadows the difficulties to come in Humes’s marriage, Mailer speaks with unusual candor about the notorious knife attack he himself made on his first wife, as well as Humes’s authoritative and rational response to this momentary and nearly fatal loss of reason. “He was a leader,” Mailer says. “It’s just that he was kind of a cockamamie leader.” In a shockingly short span of years, Humes effectively put those leadership skills to use as a filmmaker, an inventor, a City Hall-fighting radical, and a campaign manager of Mailer’s ill-fated run for mayor of New York City. Then things began to unravel.

Ms. Humes’s expert blending of period documentary footage, excerpts from her father’s uncompleted proto-avant-garde film “Don Peyote,” and some of the most well-spoken talking heads ever assembled for a single-subject documentary portrait, has the authoritative ring of well-researched and parsed third-person exposition, tempered by the affecting tenderness of first-person emotional subjectivity. On the historical side, the search for the print of “Don Peyote” is the basis for a satisfying digression into just one of Doc Humes’s hitherto undocumented efforts as a cultural pioneer. On the personal side, as Doc’s sanity takes leave in the late ’60s on the wings of unjudicious LSD use, the film darkens considerably and Ms. Humes unceremoniously details her family’s eventual dissolution with an unguarded frankness and maturity that is nothing short of inspiring. We should all be able to handle the memory of a gravely sick family member’s catastrophic meltdown with such clarity and courage.

Eventually, Ms. Humes and her siblings reconnect with their father, who has himself reconnected with reality while acting as a kind of uninvited visiting professor holding court on the Columbia campus and elsewhere, and making headlines by giving away cash. Never mind that it was his children’s potential inheritance.

“You have to seize your opportunities in life to get to know people who are remarkable,” offers the novelist Paul Auster, one of Doc Humes’s early-’70s Columbia students. “Even if they finally pulverize you.” The destructive swath that Doc Humes’s insanity and narcissism cut through his family, we learn, was in the end balanced by the piercing intelligence that he freely shared and doggedly worked to awaken in those brave enough to stick with him through the paranoia, chemical misadventures, scarring object lessons, and manipulative freeloading. The film’s coda discovery about the veracity of Doc’s later-life delusions is too deliciously ironic to describe in detail, other than to say that it gives sobering new weight to Woody Allen’s old joke that “paranoia is knowing all the facts.” It ends this fine film on an exuberant, exasperating, and crusading note that perfectly befits its subject.

Through January 29 (209 W. Houston St., between Sixth Avenue and Varick Street, 212-727-8110).