Photograph by Jay Paul/The New York Times/Redux

The snuffing out of a life, especially when the flame was still strong, is never less than a shock, and admirers of Robin Williams, who died on August 11th, will feel that they have been left in the dark. He had made no secret of his long wrestle with drugs and alcohol, nor, typically, had he hesitated to use that fight as a comic resource, beating himself up with his own jokes. To watch him in full spate, onstage or on a talk show, where he would shift and bounce in his seat like a young boy who wants to play outside, was to be nagged by a question, however naïve: Why in heaven’s name did this man, of all men, need extra stimulants? Wasn’t the simple fact of being Robin Williams, high on his own inventiveness, enough of a rush? What exhilarated us must have exhausted him, and no friends or fans, praying that he now rest in peace, would deny that the peace was hard earned.

Williams had the blessed knack—wholly unfakeable, and envied, no doubt, by grander stars—of giving those fans the impression that they were his friends. There are funny guys who seem naturally sparing, even miserly, with their wit, waiting for the curtain to rise or the cameras to roll before they can bring themselves to uncork. Williams, by contrast, was helplessly generous, popping open and spraying his audience with riffs and raps as though it had been painful to bottle them up—as though he were thanking us for giving him the chance to release. I remember, with undiminished joy, putting on a video of Williams performing live at the Met, in 1986, and seeing this stocky figure, in a deafening shirt, skip and leap onto the cavernous stage, in the footsteps of ballet dancers—“Men wearing pants so tight you can tell what religion they are.” He admitted to nerves, in that august setting, yet it was the same nerves, plucked like strings, that were making his brand of verbal music, in all its profanity and zeal.

There was a side of Williams that most Americans, secure in their homeland, never got to witness except on tremulous video clips, grabbed from the fringes of a crowd. Not since Bob Hope, I would guess, has a star proved so indefatigable in his mission to amuse American servicemen and women, who tend to need little persuading that the world is, taken all in all, nuts. (According to U.S.O. estimates, he entertained more than eighty-nine thousand of them.) Williams, newly arrived at Kandahar Airfield, in Afghanistan, in 2007, pointed out the weirdness of the environment in which the troops existed: “There’s snow there, there’s a desert, and there’s a fucking hockey rink. I don’t need drugs.” If only. Like any sane person, he drew a clear distinction between government policy and the folks up at the sharp and messy end who have to put it into effect, and, to judge by the whoop level that greeted him in 2010, when he returned to Kandahar, military personnel bore him no grudge for having called their former Commander-in-Chief “a comedy piñata.” In truth, political invective was hardly his forte; what tickled him and ignited his gibes (this, again, is a very soldierly habit) was the prospect of the stiff and the stuck-up, especially when they were lofted into positions of power. Think of poor J. T. Walsh, as Sergeant Major Dickerson, in “Good Morning, Vietnam,” whom Williams addresses thus: “You’re in more dire need of a blow job than any white man in history.” (The killer there is “white.” Williams never shied away from color or creed, with their plethora of niceties and traps. He sprinted toward them.)

To be honest, though, is that a film to which one returns, with glee, in its entirety? Might it more often be cherished piecemeal, on YouTube, where you can follow Williams, the ultimate disk jockey, in his galloping turns at the mike? Not to speak ungratefully, let alone ill, of the dead, but one has to ask whether American film, as it unrolled through Williams’s career, offered either the shape or the scope for the play of his singular talents. Many leading directors—Barry Levinson, Gus Van Sant, Terry Gilliam, Christopher Nolan, Peter Weir—entrusted him with meaty roles, and such faith is hard to quibble with, just as the warmth with which his admirers clung to films like “Mrs. Doubtfire” and “Dead Poets Society” was lasting and unfeigned. (The climactic scene from the latter—students standing on their classroom desks in worshipful tribute to Williams’s character, their departing English teacher—has been acted out afresh, and posted online, since the news of his death.) Yet something about the emotional curve on which so many films rely, as it dips into distress and then rises toward resolution and redemption, feels altogether too easy and too organized for the crazy sine waves that Williams instinctively traced in body, brain, and tongue. How many personas does he adopt in “Mrs. Doubtfire”? Two: a kindly, harassed dad and a kindly, slightly less harassed Scottish nanny. Two! In the throes of an improv routine, he could race through two in ten seconds.

The essence of Williams, in short, was the enemy of plot. So was the essence of Groucho, and, when Williams picked up the Best Supporting Actor award, for “Good Will Hunting,” at the 1998 Oscars, nothing was more apt than the low-slung, questing, Grouchian lope with which he finally left the stage and walked off into the wings: Bad Boy Hunting. But Groucho and his kin were crammed into their films to bursting point, as if into the cabin of an ocean liner; anything more elegant would have insulted their capacity for chaos, and, harp solos aside, all plangency and reverie were banned. Conversely, there came a moment in almost every Williams film when his voice would sink low, toward gentleness, and that Mr. Punch face would crumple and crease into a soft smile; you find it not just in the sappy work, like “Patch Adams,” but also in more sober scenes—the park-bench talk, for instance, in “Good Will Hunting,” where Williams handed worldly wisdom to Matt Damon, like a bearded magus. Even as he reflected on the Sistine Chapel, however (“You’ve never actually stood there and looked up at that beautiful ceiling”), I found it impossible to suppress heretical thoughts, musing on what Williams the standup would have done with God, Adam, and their nearly touching fingers. The Pope would have made an entrance, too, you can bet on it. Indeed, it is hard to remember any of Williams’s more solemn roles—in “Awakenings,” or “What Dreams May Come”—that he would not, on a different day, before a live throng, have hastened to make sport of and whip into a routine.

To argue the case for frivolity, or the need to lampoon, is not always a cynical request. Might it not be the case that pathos—even, or especially, at its most sincere, tugged directly from the heart—is in fact a fairly common currency, whereas the gift bestowed on Williams, with his relentless coining of bright new characters and sounds, is the rarest of riches? We speak of cheap jokes, but not all tears are costly or precious, as an evening of talent shows will confirm, whereas the best jokes are priceless; that is why we hoard them, for years, and bequeath them to the next generation. Not that Williams was just a minter of gags. He could rattle off one-liners, to be sure, and many of them were stinging and smart, but what we treasured him for was the rattle itself—the jolting sensation that he alone, and sometimes not even he, knew exactly where his mind would send him next. How could Hollywood, home of the safe bet and the sure thing, be expected to cope? Was there ever a time when he was captured on film, yet set free?