Jerry Lewis sits behind his huge desk, neatening the items that stand like sentries between us: a can of Diet Sunkist; a container of silver pens, tips up; a container of red pens, same position; a handful of green plastic surgical scalpels he uses to open mail, a dish of lemon drops. When you've been on the planet for almost nine decades, like Lewis has, and when you can't throw anything out ("I've kept everything!"), and when you're slightly nuts ("Did you ever see a man who can look at one eye with the other?"), you require order. At 85, Lewis employs three full-time people to help him stay organized. He loves them fiercely—and drives them bonkers.

"Have you done anything today? Why not?" Lewis likes to bellow, his voice—three parts affection, one part curmudgeon—thundering through Jerry Lewis Films, a sprawling suite in an office park about four miles from the Las Vegas strip. He looks good—a little stooped, sure, but still sharp-eyed and quick-tongued and up-tempo, his red silk shirt unbuttoned low enough to reveal the scar from his double-bypass surgery twenty-nine years ago. On his feet are red velvet slippers embroidered with those iconic faces of Comedy and Tragedy. "Can I get another orange soda?" he asks, and when it arrives twenty seconds later: "What took you so long?"

Suddenly, Lewis's face goes blank and his hazel eyes get big as quarters. Slamming his chair back—boom!—he reaches for a trash can under his desk and expels a mouthful of soda in its general direction: a classic spit take. Except, he says, that it's not.

"Went down the wrong pipe," he announces, daintily dabbing at his mouth with a napkin. "I'm fine. It happens all the time, and when it does, you just have to let it." Getting older is crammed, he says, with such losses of control. "I'm taking Lasix, which makes me pee sometimes seven, eight, eleven, twelve times," he says. "I've decided to keep my fly open all day."

For hours now, we've been sitting around talking about funny—what it is, how it works, how to kill a joke, how to let it breathe. Lewis has thought a lot about these things since he got his first onstage laugh, accidentally kicking out a stage light at the age of 5. That was in 1931. In the intervening years, he became and remains the reigning master of the sight gag, the clown with the rubber face whose links to the foundations of American comedy are unmatched by anyone alive. This is a man, after all, who was tight with Charlie freakin' Chaplin, not to mention Stan Laurel and Al Jolson. This is a man who's met nine presidents and performed for four. As we talk, photos of many of those he holds dearest, may they rest in peace, look down from his crowded walls: John F. Kennedy, Frank Sinatra, Sammy Davis Jr., and the handsome crooner Lewis still calls "my partner" even though they broke up their act fifty-five years ago: Dean Martin.

In the 1940s and '50s, Martin and Lewis were—along with Sinatra and Elvis—the most famous people on earth. Later, though American critics were slow to recognize it, Lewis also became one of the few comic auteurs: a filmmaker who wrote, directed, produced, choreographed, edited, and starred in many of his own films, the best of which (The Nutty Professor, The Bellboy) have become bona fide classics. Tarantino and Spielberg are avowed Lewis fans. So is Scorsese. "He makes many people uncomfortable," the director says. "He doesn't censor himself as a performer, a filmmaker, or a public figure—which is difficult to accept for many people. I know there have been some books about him and some recognition in the past few years, but I think Americans are still coming to terms with Jerry and his astonishing artistry. It's as if they had to invent a new place for it, a new category.