Last week the NY Times marked the passing of Kevin McCarthy, veteran stage, film, and television actor most famous for his leading role in the original Invasion of the Body Snatchers (I will always remember him as the cartoonish villain in the utterly ridiculous UHF).
The biggest distinction between stage actors and screen actors is one of work ethic -- to reach the pinnacle of one's craft in the latter means large payouts in exchange for as little effort as possible, while in the former to be at the highest levels is to work exhaustively.
McCarthy, throughout his career, was a stage actor in temperament:
Despite his film and television success Mr. McCarthy never abandoned the stage. The 18 Broadway productions in which he appeared included Moss Hart’s “Winged Victory” (in which he was billed as Sgt. Kevin McCarthy), the political drama “Advise and Consent,” Chekhov’s “Three Sisters” and Kurt Vonnegut’s irreverent “Happy Birthday, Wanda June.”
[...]But in 1991 he told a critic for The San Diego Union-Tribune about his feeling that purposeful employment was a remedy for many ills. “I try to get as much work as I possibly can,” Mr. McCarthy, then 77, said. “I love to work. I love to be in things.”