Image Frank Tommasini celebrating his 99th birthday last fall with Anthony Tommasini. Credit... Anthony Tommasini

I admire the character of John Maclean in “A River Runs Through It” and sense the deep, if unspoken, closeness within his family, which emanates especially from their modest mother (the always affecting Brenda Blethyn). Yet what still baffles me about this erudite father is that he seems not only unable to help Paul, but almost unwilling to try. It’s as if, according to his understanding, the Christian way is to respect the free will of every adult, even when it’s your reckless son.

As we see in early scenes, John Maclean brings up his two boys, Norman, three years older, and Paul, by imparting strict moral and educational codes and instilling in them his own devotion to fly-fishing. Norman, narrating the story years later (voiced by Redford), explains: “In our family there was no clear line between religion and fly-fishing.” After all, as the father liked to point out, Jesus’ disciples were fisherman.

John home-schools the boys. And if the lessons include any math or science, we see no evidence. Their curriculum seems focused on reading books and writing essays about what they read. John Maclean would have been a brutally effective newspaper editor. He takes the essays, makes corrections, then tells his sons to rewrite them so they’re half as long. When they do so, he makes more corrections, then demands they trim by half again! Only when the daily essays are concise and clear are the boys free to catch trout from the river.

Both sons wind up choosing writing professions. Norman (a stalwart, sensitive Craig Sheffer), attends Dartmouth and is away for six years. When he returns, Paul has become an enterprising reporter for a newspaper in Helena. He has also grown into a master fly-fisherman, devising techniques unknown even to his father.

As children the boys routinely fished with their father. Now that the brothers are independent adults, these outings, filmed with plush, enthralling imagery, have become intense male-bonding sessions where feelings are deep but words are few.