Albert Finney was not yet 50 when he earned his third Oscar nomination playing a volatile ball of ego and insecurity in Ronald Harwood’s brilliant backstage drama “The Dresser.” At one point, the character — a high-maintenance Shakespearean stage actor slowly collapsing in upon himself like some kind of dying sun — bellows, “I can’t do it anymore! I have nothing more to give!”

That was 35 years ago. His character Sir may have been primed to expire after more than 200 performances as King Lear In “The Dresser,” but Finney, who died Thursday, still had at least half of his career — and two more Oscar nominations — ahead of him: as the epically self-destructive drunk in John Huston’s “Under the Volcano,” and the surly boss-turned-champion in “Erin Brockovich.”

Younger audiences probably know the 82-year-old British actor best as the baritone-voiced mastermind behind the shadowy CIA operations in the first two Jason Bourne sequels, or else as the groundskeeper of James Bond’s estate in “Skyfall.” I grew up thinking of him as Daddy Warbucks in Huston’s 1982 screen adaptation of “Annie,” while a previous generation of kids saw him a dozen years earlier as the miserly Ebenezer in Ronald Neame’s “Scrooge.”

But Finney’s most significant contribution occurred a decade prior, when the dashing young star did his part to evolve what we think of as great acting. Though he had trained at the Royal Academy of Dramatic Art as a Shakespearean leading man, Finney went a completely different direction in film, playing contemporary rapscallions and characters of ruthlessly modern sensibility. His style also diverged from what was happening on the American stage and screen at the time, where Marlon Brando and his peers had been innovating “the Method” on the other side of the Atlantic. Instead of embracing Stanislavski’s system, Finney married technical mastery with a kind of spontaneous, unpredictable energy, resulting in characters who felt simultaneously representative of the moment and almost radically ahead of their time.

After seeing Finney deliver a pair of magnetic performances in “The Entertainer” and “Saturday Night and Sunday Morning,” director David Lean reportedly wanted him to play the title role in “Lawrence of Arabia,” but Finney declined. And so, the part that effectively launched his screen career was the lead in “Tom Jones” — a runaway phenomenon whose massive popular success (Tony Richardson’s 1963 film won four Academy Awards, including best picture, and earned Finney his first Oscar nomination) sprung from its radically irreverent handling of a respected British classic, a combination perfectly suited to Finney’s unique screen persona.

Richardson’s go-for-broke adaptation connected with audiences as few films had, revolutionizing British cinema, even as it helped to spark a massive cultural shift that would set London swinging in the ’60s. Characterized by bawdy sexual escapades and a raucous attitude that prized youthful indiscretion over centuries of class-based propriety, Tom Jones was, quite literally, a “lucky bastard,” and Richardson’s go-for-broke approach called for a dashing young actor to dismantle the tradition of polite period performance in favor of something wild, anarchic, and gleefully self-aware.

Clearly, no Method actor could have done the job, if only because the film’s radical view of honesty in performance depended not on accessing raw emotional truth deep within, but a kind of sly sort of acknowledgement between audience and star that everyone was in on the same joke. To drive that home, Finney breaks the fourth wall at several points, gazing directly into the camera to acknowledge the absurdity of the situation at hand.

It was there, in “Tom Jones,” that audiences first caught what would become the signature twinkle — and figurative, conspiratorial wink — in Finney’s eye, visible in varying forms in nearly every role he’s played since. You catch it in his blood-chilling turn as the Irish crime boss in “Miller’s Crossing,” a next-best variation on Brando’s iconic mafia pater familias in “The Godfather.” And it’s clear in the scene where Finney delivers a $2 million bonus to Julia Roberts in “Erin Brockovich,” holding back a smile for the audience’s benefit as he endures her tirade about being undervalued at the firm.

That cheeky brand of self-awareness is the defining quality in what I consider to be Finney’s best role, as the hitchhiking womanizer who picks up Audrey Hepburn (or is it the other way around?) in Stanley Donen’s 1967 “Two for the Road.” Whether sneaking sideways smiles at the camera or giving his best Humphrey Bogart impression, Finney puts his charms in service of a character who’s constantly in seduction mode, even long after meeting — and marrying — the woman of his dreams, finding the arc in a character who goes from being “a bad-tempered, disorganized, conceited failure” (in the words of Frederic Raphael’s Oscar-nominated script) to “a bad-tempered, disorganized, conceited success.”

Though underappreciated at the time, the rip-roaring two-hander still feels cutting-edge today, in part because it approaches the ups and downs of marriage in honest, adult terms, but also thanks to the nearly-whiplash-inducing way it ricochets through a dozen years — and several trans-European road trips — in the span of a couple’s relationship (the average shot is something like seven seconds in this rapid-cut marvel). We all have our favorite Finney performances, but “Two for the Road” is the one that I imagine comes closest to the man himself, the role where rueful honesty aligns most perfectly with the way he could enlist an audience in confederation with his characters.

Over the course of a more than six-decade screen career, Finney gained and lost weight for his roles, transformed his appearance, and shaved his head as he deemed necessary to create an unforgettable character. All the while, he continued to work in theater, even stepping away from the screen for a nearly-seven-year stretch — following his eccentric, Oscar-nominated turn as Hercule Poirot in “Murder on the Orient Express” — during which he tackled Hamlet, Macbeth, and Uncle Vanya on stage.

He gave and he gave, and though many of us were never fortunate enough to see him walk the boards, because so much of his work was captured on celluloid, we are left with an indelible record of so many of those great performances, that spark in his eye never to be extinguished.