Formidable he was — six feet tall (which sometimes seemed like seven), severely black-suited, and able to look right through you, or more often over you. Barbara Milberg Fisher, an NYCB soloist in the 1950s, in her charming memoir of the early days In Balanchine's Company, writes, "I never saw him smile." Her colleague Anne Crowell has compared his dour expression to that of the stones on Easter Island. Others thought he resembled an eagle — or even Moses. Forbidding images, all. Yet everybody (including this writer) called him simply Lincoln.

Much has deservedly been written about Kirstein's sterling place in the development of the arts in America in the 20th century. In addition to his service to dance — starting with bringing Balanchine to America and co-founding the School of American Ballet, and including unreserved devotion to New York City Ballet for the rest of his life — he was an advocate (often behind the scenes) for artists, photographers, actors, musicians, and writers. He painted, worked in a stained-glass factory, wrote several books on dance (and on many other subjects), and even, despite his size, studied ballet. (Always a man of taste and erudition, he chose for his teacher none other than the legendary Michel Fokine.)

In this centennial year, some friends and co-workers have recalled a more personal side of Lincoln. There were many unsung acts of kindness. Jillana, a Principal Dancer in the 1950s and '60s, tells the story of a long, long night at the airport, with parents and friends waiting for dancers on a much-delayed flight home from a European tour. Lincoln was there the whole time, waiting like everybody else, and treated the entire group to hamburgers and coffee.

"He had an enormous heart," says British-born Leslie ("Ducky") Copeland, director of men's wardrobe at NYCB for 47 years, who suspects Lincoln was somehow involved in his citizenship test, since he seemed to know an awful lot about the examining officer. Lincoln gave Serapio Walton, NYCB's music and video archivist, his first pair of contact lenses. He gave a West African figure, the first art he ever bought (at the age of 15), to his editor Harvey Simmonds, because Harvey was born in Liberia.

He never stopped caring about the Company. Except on weekends, he was at every performance, sitting in the first row of the first ring. Perry Silvey, NYCB's Director of Production, recalls Kirstein rushing backstage one night at half hour to inform the crew that a chair had inadvertently been left in front of the curtain. After it was discreetly whisked away, says Mr. Silvey, "He didn't berate us (which would have been his right) or even try to make us feel guilty (which would have been redundant), but acted like he was just being helpful and was proud to be a part of making things go smoothly." Lincoln was always there.

Everyone who came into contact with him on a personal basis was soon aware of his love for cats (a passion he shared with Balanchine). Many dancers recall parties in Kirstein's elegant townhouse, which was crammed with beautiful art (including paintings on the ceiling). He delighted in discussing his art collection with his guests, but what seemed to give him the most pleasure was opening a certain large cabinet and gleefully displaying its contents — glass cats, porcelain cats, salt-and-pepper shaker cats, and a myriad of other cats — some "artistic," some most definitely not so.

Meanwhile, a living member of the feline world might be reclining on a nearby bust of Napoleon, or on a silken couch, or on a harpsichord. Maitland McDonagh, NYCB's press officer in the 1980s, herself a rabid lover of cats, writes of Lincoln's obsession, "I always thought the reason somebody like Lincoln liked cats was that, unlike dogs, they will never adore you; they will always demand that you show them that you are worthy of their attention. They have an incredible innate grace. And they walk with the conviction that the world was made for them." In cats, it seems, the awe-inspiring Mr. Kirstein may have met his match.

Kirstein was a man of contradictions, by turns patient, willful, kind, impatient, irascible, loving, dismissive. But he was always brilliant — a giant of his time. We may never know his full measure.

Nancy Reynolds danced with NYCB and is now a dance historian. Her books include Repertory in Review: 40 Years of the New York City Ballet and a comprehensive history of 20th-century dance, No Fixed Points (with Malcolm McCormick).