You can trust Ed Harris to locate the essence of every character he portrays. And in “That’s What I Am,” Mike Pavone’s righteous reflection on bullying and tolerance, Mr. Harris’s depiction of a saintly, soft-spoken, bow-tie-wearing middle-school teacher lends the movie a moral weight it probably couldn’t have summoned had another actor played the role.

Set in 1965 in a small Southern California town, “That’s What I Am” is a sentimental Hallmark-style movie (part after-school special, part “Wonder Years” offshoot) whose narrator, Andy Nichol (voiced by an uncredited actor who sounds like Greg Kinnear), looks back on his middle-school experience. His beloved teacher, Mr. Simon (Mr. Harris), is first seen reading to a class from Mark Twain’s “Personal Recollections of Joan of Arc.” This choice of literature sets him up as a martyrlike figure.

Later in the movie, when a bully retaliates against Mr. Simon’s discipline by spreading unfounded rumors about his sexuality, the teacher, a widower, refuses out of principle to deny the rumors. At this point you wonder if “That’s What I Am” will turn into a movie about a vicious, small-town witch hunt, but it is too timid to go there. It is more interested in the buildup to Andy’s first kiss with Mary Clear (Mia Rose Frampton), a kindhearted, more experienced classmate.

The movie’s depiction of the savage pecking order of school is mild; the children, obsessed with “cooties,” seem naïve even by 1965 standards. The principal outcast, Stanley (Alexander Walters), a k a Big G (for the ginger hue of his hair), is a tall, gawky boy with big ears who comports himself with unshakable dignity when faced with peer-group persecution. The 12-year-old Andy (Chase Ellison) learns to respect Big G after Mr. Simon assigns them to collaborate on a project.

Because “That’s What I Am” is a production of WWE Studios, it slips in a wrestling star, Randy Orton, as the lying bully’s rabidly homophobic father.

At heart “That’s What I Am” is really a gentle, earnest illustration of a slogan that Mr. Simon submits in a contest to come up with a solution to world peace in 25 words or less. His entry, which he scrawls on the blackboard, reads “Human dignity + compassion = peace.” It wins him a flashy car.

“That’s What I Am” is rated PG (Parental guidance suggested). Its cursory discussion of homosexuality may offend certain viewers.

THAT’S WHAT I AM

Written and directed by Mike Pavone; director of photography, Kenneth Zunder; edited by Marc Pollon; music by James Raymond; production design by Raymond Pumilia; costumes by Claire Breaux; produced by Denise Chamian; released by Samuel Goldwyn Films and WWE Studios. At the Cinema Village, 22 East 12th Street, Greenwich Village. Running time: 1 hour 40 minutes.

WITH: Ed Harris (Mr. Simon), Chase Ellison (Andy Nichol), Molly Parker (Sherri), Daniel Roebuck (Jim), Randy Orton (Ed Freel), Daniel Yelsky (Norman), Alexander Walters (Big G), Mia Rose Frampton (Mary Clear) and Amy Madigan (Principal Kelner).