NEW YORK--Exposure to the large spirit of Charles Dickens should be on a grand scale. It is, for those who spend 81/2 hours in early Victorian England at the Royal Shakespeare Company's splendid production of a play wrought from Dickens' sprawling novel "Nicholas Nickleby."

This is an age choking on products that are frivolous in conception and shoddy in execution. But 42 actors playing 137 roles on a set that is a masterpiece of stagecraft have produced, with passion, a gem. They have recreated the world that Dickens, God- like, created and filled with a riotous variety of the sort of people we shall forever describe as Dickensian.

Much has been made of the $100 ticket price. That is 20 cents a minute (three cents a minute less than a lot of Broadway fluff). When the 14-week run ends Jan. 3, just 55,000 people will have seen it (about half the attendance at a University of Michigan football orgy). And the producers will have about broken even.

By bringing "Nicholas Nickleby" to Broadway, they have done the sort of thing Nicholas and other Dickensian heroes do--a glittering deed in a naughty world.

Dickens has been called the least artistic great artist, and he certainly is the most popular fine novelist in the language. Most of his writings appeared first in serial form in popular publications, cheek-by-jowl with journalism, as entertainment, sort of like today's comic pages. Sort of.

It is sometimes said, dismissively, that Dickens wrote "cartoons," meaning that he simplified and exaggerated virtues and vices. But today's cartoons are . . . cartoons. We have declined from Dickens to Doonesbury. Doonesbury and "MASH" and other entertainments dabble at wisecracks and call the dabbling "social commentary." But Dickens changed society, improving and saving lives. Debtor prisons, courts, the "Yorkshire schools"--those prisons for unwanted boys that are one subject of "Nicholas Nickleby"--are among the many wrongs that he helped to right.

He may have been too sentimental for today's "realists," but he left a legacy of improvement, which they are not apt to do. He was an especially effective advocate for children. In his day, children were still tried in courts with adults, and "education" still aimed at "breaking the child's spirit." Few novelists write much about childhood, perhaps because its complexities are as many, and more mysterious, than those of adulthood. Most adults have pruned their dreams and narrowed their focus and become relatively (relative to children) simple. Dickens, in "Nicholas Nickleby" and elsewhere, took the terrors of childhood with the seriousness of a man who could really remember being a boy.

A critic, arguing that evil is more interesting than good, says: "Take someone to the zoo and he wants to see the snakes." At the end of the play "Nicholas Nickleby," audiences rise and applaud, rapturously, the kindly creatures in the human zoo. Is Nicholas, standing there at the end with an orphan in his arms reminding us that there is always another child to be comforted, "too good to be true"? He is, if we think so. Thinking of him as impossibly noble can make us unnecessarily discouraged about our capacities.

G.K. Chesterton, a Dickensian figure in his physical abundance and his more than ample confidence in the common people, wrote that whereas a poet in the Middle Ages inscribed "Abandon Hope All Ye Who Enter Here" over the gates of Hell, modern writers inscribe that over the gates of this world. But over the gates of Dickens' tumultuous world is inscribed the injunction to abandon hopelessness and all the pleasures of pessimism.

Dickens defies the persistent attempts to force him into the ranks of the political left. As George Orwell said, in every attack on society Dickens is "pointing to a change of spirit rather than a change of structure." Dickens is the keeper of the flame that lights the world's dark corners, the faith in social regeneration through personal regeneration.

Orwell, with his disdain for "smelly little orthodoxies," distilled Dickens' doctrine into 10 words: "If men would behave decently, the world would be decent." That lacks metaphysical flourish, but it has the not inconsiderable virtue of being true.

Unlike John Osborne and the other "angry young men" of the postwar theater, Dickens was, in Orwell's phrase, "generously angry." In Osborne's "Look Back in Anger," the protagonist, Jimmy Porter, says: "There aren't any good brave causes left." Dickens' message, which has found an avid audience on Broadway, is that the worthiest cause is kindness, and it is timeless.