How odd to celebrate someone for not being who we’ve been programmed to expect. But American entertainment worked hard on the mold that Cicely Tyson refused to fit. So, really, what we’ve been saluting all these decades was historic defiance. She died on Thursday, at 96, just after the release of “Just as I Am,” a juicy, honest, passionately Cicely memoir. (“Well, child, I’ll tell you: my mouth fell open like a broken pocketbook.”) And on the opening pages resides the truth about why, as a performer, she was the way she was.

“My art had to both mirror the times and propel them forward,” she writes. “I was determined to do all I could to alter the narrative about Black people — to change the way Black women in particular were perceived, by reflecting our dignity.” Tyson made this vow in 1972, a few years after the assassination of the Rev. Dr. Martin Luther King Jr., at the dawn of the so-called Blaxploitation filmmaking boom that didn’t fulfill her. No hookers, no servants, no big bad mamas. Which meant that, for a woman dependent on an industry that trained its patrons to overlook a beauty as singular and angular and walnut-brown as hers, she’d essentially declared a hunger strike.

Alas, she would not be playing the most daring, out-there characters. And let’s face it: the great parts were always headed to someone whiter anyway. The more audacious move was to declare herself a moral progenitor, to walk with her head high so that Denzel Washington might become a man on fire and Viola Davis could learn how to get away with murder.

Tyson had a remarkable physical presence, someone sculpted as much as born. Her body was dancer lithe. She seemed delicate. But only “seemed.” She was delicate the way a ribbon of steel holds up its part of a bridge. The deceptive nature of her fineness was right there in the name. Cicely Tyson. Poise and punch.

Her mouth comprised an overbite, protruding front teeth and two full lips. The words she spoke brought with them a little extra breath, which, in turn, gave her an everlasting lightness that made us lean toward her so we wouldn’t miss whatever truth she was about to tell. She didn’t write the scripts, yet she never seemed to waste a word. How? And the way she spoke: with the erudite diction fragrant of both old showbiz and old Harlem. No Black woman had ever performed this reliably with this much elegance and surety. Of course, the mold being what it was, nobody had ever asked a Black woman to do any such thing. (Diahann Carroll appeared to be her sister in dignity.)

Tyson was a peculiar kind of famous. I was never told of her importance. I just knew. Everybody knew. This woman was somebody. She looked sainted, venerated — at 29, 36, 49 and 60. Even in anguish. It’s possible that happens once you’ve played a 110-year-old formerly enslaved woman in “The Autobiography of Miss Jane Pittman” and after you’ve played Kunta Kinte’s mother. Or maybe those roles happen because you radiate venerability.

She could act with her entire head yet scarcely move it at all. That’s her in most of “Sounder,” transfixing in her stillness. “Sounder” itself is a quiet, Depression-era movie, from 1972, built around Louisiana sharecroppers named Nathan and Rebecca Morgan, their three children and the family dog, Sounder. It’s foolishly lit. The night scenes are brightened by lanterns, which wouldn’t be my first choice for a movie with this much brown skin. Tyson spends a few scenes under a big straw hat that hides half her face.

For lots of actors this would be death, because they’re too vain to stand for it or lack what it takes to overcome that kind of obscurity. For that sort of actor it’s all in the eyes. Over four decades of watching this woman work, I discovered that her technique rarely relied on her eyes, although they could glitter and dance. Tyson was another sort of actor: a life force. She emanated and exuded: hurt, warmth, joy, suspicion, fear, hauteur, love — an ocean of love.

CICELY TYSON WAS known to all people. But in Black homes, Tyson epitomized “household name.” A fixture even more than a star, either way an illuminant. A natural resource, a wonder, a font, a dream, a beacon. What other actor worked with such clear purpose, vocation and seriousness on the one hand and with a devastating smile on the other? Tyson knew what she represented. An honorary Oscar, three Emmys, a pile of Emmy nominations and a Tony all came her way. Just as fittingly for a woman who willed herself to matter, so did eight N.A.A.C.P. Image Awards.

One of those was for playing Marva Collins in “The Marva Collins Story,” a pat yet ultimately astonishing Hallmark Hall of Fame production that CBS aired in 1981. Collins taught at a Chicago public school that the movie turns into a zoo everywhere but inside her classroom. It’s quintessential Tyson. The school system’s bureaucracy and low expectations inspire Collins to open a private school in the upstairs unit of her house. When a white teacher all but calls her uppity, Marva treats her to a death stare and says, “I dress the way I do, Miss Denny, because I happen to believe my children deserve a positive image.” Tyson is loose and charming and sharp; married to a carpenter played by Morgan Freeman; romantic, funny, unflappable and — thank the lord — well lit, the teacher of parents’ dreams, the actor this country needed in more slam-dunk roles just like this.

Consider the parts she could have played if the movies were fairer. Consider what we’d be saying now if her standards were lower. How’s that for fairness?

I often got the sense that Tyson was hanging on to a little something, perhaps for herself, which, in turn, compelled us to hang on more tightly to her. In “Sounder,” after a judge sentences Nathan to a year of hard labor, the film cuts to Rebecca, seated in the rear of the court surrounded by her children and two friends. Rather than wail, she just looks on in solemn comprehension, a hand supporting her head. Of course, she’s devastated; the marriage is strong. But in that moment, what you see Tyson performing is resolve, strategy. She knows that she now has to do the farming — the sharecropping — on her own. The moment hits you harder for all that Tyson doesn’t do. Poise, punch.

She rarely broke down. She never cracked up. She held it together, lest the rest of us fall apart. “Marva Collins” was as close as Tyson ever got to her wits’ end. And even then: she was losing it for her people. There were other exceptions. The scene in “Sounder,” say, in which Nathan, freshly sprung from that labor camp, hobbles up to the road as she runs a 100-yard dash toward him, tears flying from her face, her arms flung open. This is no way to run a dash. Instead, she invented a run powered not by muscles at all but entirely by heart. That sprint goes in the national registry of great American movie shots. And how about when ancient Miss Jane takes that drink at the “white only” fountain? You can show that to a Martian and he’d wipe the water from his mouth.

Tyson knew her place. It was in our movie palaces and living rooms, but also at Black families’ kitchen and dining room tables, an emblem of her race, a vessel through whom an entire grotesque entertainment history ceased to pass because she dammed it off; so that — in her loveliness, grace, rectitude and resolve — she could dare to forge an alternative. She walked with her head high, her chest out, her shoulders back as if she were carrying quite a load that never seemed to trouble her because she knew she was carrying us.