All his life, the ways of J. Roderick MacArthur have been those of a fighter in a hurry. He is dying from cancer of the pancreas, but his habits of 63 years remain exactly as before: feisty, hurried, blunt, iconoclastic.

"I feel good when I feel good and bad when I feel bad. I have good days and bad days. Chemotherapy sometimes has unpredictable effects. I don't quite like it. My digestion is all shot to hell. My pancreas isn't working quite right."

There are no odds to be cited. Mortality is closing in. But MacArthur, a slightly-built man with a challenging, antic gleam in his eyes and a handsome brigadier's mustache that complements his mane of white hair, can't stop fighting. It's in his blood; it's his history.

The self-made multimillionaire son of a self-made billionaire insurance salesman, Rod MacArthur has had a life studded with commercial and legal struggles as well as headline-making fracases with various members of his own clan..

There was the fight with federal banking officials who thought his invention of NOW checking-savings accounts was criminal. He won that one. There was the fight to create cheap supplemental medical insurance for average Americans. He made millions from that one. There was the fight with his tight-fisted, tough father for control of the Bradford Exchange, a company Rod MacArthur invented which organized and now controls the lucrative worldwide exchange of collectors' commemorative plates. It took a daylight raid to repossess thousands of plates, but Rod MacArthur won that one, too. There is the continuing struggle with the directors of the very foundation his father established, about which more later.

But of all his campaigns against the grain, perhaps none has been as discussed, envied, celebrated -- or condemned -- as much as Rod MacArthur's inspiration to give money to "geniuses." The MacArthur Fellowship Grants program, which he directs, provides tax-free stipends of $24,000 to $60,000 yearly for five years to recipients.

One hundred sixteen persons, most of them men, have been named MacArthur Fellows since the program began in May 1981. Their stipends total $22 million, less than a drop in the bucket for the parent John D. and Catherine T. MacArthur Foundation, which is worth about $1 billion. New fellows are to be named soon, after a secret selection process.

The program's critics fault it on grounds that it has no clearly established goals. There are no strings attached: the "genius" can do with the money whatever seems right (or wrong), from continuing the work that first attracted the foundation's attention, to starting something else, to buying a yacht, to giving the money away -- no strings attached -- to someone else.

MacArthur, who talked to a visitor at his office at the Bradford Exchange in this Chicago suburb, has little sympathy for the notion that necessity is the mother of invention. "It's all very well to starve in a garret, but some areas of endeavor can't be handled that way. I don't think that keeping people poverty-stricken is going to help their creative juices. I believe that they the grant recipients need the money and that most people spend a hell of a lot of time worrying where their next buck is coming from. They lose tremendous amounts of time just by the economic pressure."

Another source of criticism is that some recipients have been septuagenarian artists and scientists, such as Robert Merton, 74, an emeritus professor of sociology; Paul Kristeller, 78, a renaissance historian; and Robert Penn Warren, 79, the poet and novelist. It is imagined that the elderly are past their prime creative years and likely to have smaller financial needs anyway.

MacArthur, whose own life is being cut short by the same painful, irreversible cancer that killed his father, finds this hand-wringing absurd.

"It seems to me that whenever you try to do something new, all of the helpful people who want to be helping like crazy find all kinds of ways to improve things. And part of what they do will only make it more complicated.

"There's lots of talk about changing the MacArthur Fellows so that it applies to scientists so that, you know, they can buy test tubes or whatever -- or to give it to younger people. Or maybe a poet doesn't need as much money as an engineer . . . You know, making it more like a standard grant. This is bull. The whole idea of the grant program is not to do any such thing, but to give them freewheeling chances."

Something in the heart of a commercial society like ours responds to Get Rich Quick schemes of almost any kind. The MacArthur Fellowships fall precisely into that area where myths seem likely to be made: a rags-to-riches grant rivaling the mammoth state lotteries. Probably for this reason, the MacArthur stipends have drawn widespread attention and headlines. Rod MacArthur delights in the attention every time they are announced.

For a man who has hurried from peak to peak, MacArthur seems remarkably calm in acknowledging that this pet innovation in philanthropy hasn't yet yielded any great discoveries. "I think it will take a decade," he says, "before we really can say that is happening."

Such philosophical distance -- such downright patience -- seems somewhat unusual for this activist humanitarian who has concentrated so much energy on getting results, fast. But his own life offers ample illumination of the try-try-again approach.

"There has to be room to make mistakes," says MacArthur, who was raised mostly by his mother. (His parents' marriage broke up when he was a child.)

He attended Rollins College in Florida, and as World War II approached, traveled in Mexico -- to keep himself out of the hostilities, he says. "I was dodging the draft. In those days, if you left the country before you were 21, you didn't have to register. I stayed down there till they changed the law. Then I rushed back to the U.S. and re-registered. I was scared that we draft dodgers would get the worst treatment. It turned out that they never touched anybody."

MacArthur joined the American Field Service as an ambulance driver, served with distinction during the Allied invasion of southern France, earning the croix de guerre, France's top military honor. He finished the war as a part-time correspondent for United Press. He stayed on in Europe, dabbled in fashion photography, married and returned to the United States.

He worked for a time as editor of Theatre Arts magazine, quarreled with an uncle, and left to join his father, John D. MacArthur, once the poorest of the talented, eccentric MacArthur family of seven brothers and sisters. Among the more successful of this group of siblings were Alfred and Telfer, an insurance man and publisher, respectively. There was Charles, coauthor with Ben Hecht of "The Front Page," a Hollywood screenwriter, husband of Helen Hayes, dashing, witty, famous.

And then there was John D. "He was the poor relation," remembers Rod, the only son, who speaks of his father readily. "He was a ne'er-do-well. He was never going to amount to anything. He drove broken-down cars and left them . . . He was always trying one thing or another that didn't work. The others looked down their noses at him."

But John D. went to work for his brother, Alfred, selling insurance. After a few years, he had learned enough to strike out on his own. In 1928, he bought a tiny firm, the Marquette Life Insurance Co., nursed it through the Depression and made it grow. But it wasn't easy. Marquette Insurance, for example, had a small office in the Marquette Building, a famous landmark in the Chicago Loop. "He rented space there so people would think Marquette Life owned the building. But the rent was too high, he had to move out."

Many years later, when John D. had plenty of money, he bought the entire building. "It was kind of an emotional satisfaction for him to one day be able to buy the whole damn thing."

In 1935, the father made the purchase that ultimately led him to his billion: He paid $2,500 for a struggling firm called Bankers Life and Casualty Co. By 1940, the company had $1 million in assets. The secret was the old man's genius at direct mail sales of cut-rate insurance to Mr. and Mrs. Middle America.

By the time Rod MacArthur joined his father, Bankers Life had grown into an empire that just continued to get bigger under John D.'s unerring direction.

Rod MacArthur was installed as manager of new business for the Citizen Bank and Trust Co. in suburban Chicago. Very shortly, the son showed the same sales flair as the father. Rod was supposed to do no more than dream up ways to promote the bank. Instead, he thought up what now is commonly called a NOW account -- savings accounts with check writing flexibility.

Naturally, he went one step further: he called them USA accounts -- united security accounts. The USA accounts attracted more than $100 million in new deposits to the bank. "Other banks got very, very upset about it. And the Federal Reserve literally rewrote the regulations to try to put me out of business . . . So I changed it very slightly and kept right on going, and they threatened me with all sorts of stuff." Eventually his father worked out a verbal agreement with the Fed "and the accounts have been operating ever since worth $140 million."

Rod soon got another assignment from his father, who by the mid-1960s was spending much time in Florida with his land deals. The son took over Marquette Life, the original building block in the empire. Taking a leaf from his father's successful book of sales to caddies and pro shop managers rather than to country club members, Rod devised a low-cost Medicare insurance supplement policy, called Magnum Medicare. More than a million new customers were signed up within a few years.

"I developed the biggest mail order insurance they ever had," Rod says with satisfaction and, just maybe, an eye on his father's reputation as a mail order genius. "In fact, I guess it was the biggest mail order insurance campaign in history."

Even so, it was hard to get a raise out of John D. Fifteen years ago, Rod MacArthur was earning $20,000 a year. "We made a lot of money, but all of it was for my father. For him. I didn't get any of it. I asked him for a raise and he said, 'You don't need a raise, you just have to pay more taxes.' . . . He paid himself very well until he got eligible for Social Security. Then he paid himself very little in salary so he could collect his Social Security.

"He really was very, very frugal with himself. He didn't go in for fancy cars or yachts or things like that." For a time, John D. had an executive airplane, "with tables that came out of the floor and all kinds of stuff. But it made him so unhappy to think what that thing was costing him when it just sat on the ground -- he just couldn't stand the thought of it, so he got rid of it."

Another money-loser John D. MacArthur owned was a mail order firm called Macmart. But instead of selling it off like his corporate plane, MacArthur asked his son to see if Macmart could be made profitable. Rod discovered through Macmart that collectors around the world were buying and selling china plates to each other. Produced in limited editions of up to several thousand copies each, the decorative plates were convenient and easy to ship from place to place.

As he probed further, he saw that here was a whole marketplace, with collectors, investors, speculators, hedgers, scalpers -- the works. A porcelain duplicate of the rare coins or stamp collectors' market, it had grown in a disorganized and largely unheralded fashion ever since 1895, when Denmark's Bing & Grondahl china works commemorated Christmas by producing a blue-and-white china plate titled "Behind the Frozen Window," depicting the Copenhagen skyline. Few ate off those 50-cent plates. Instead, they collected them. That fact alone made them more valuable. The 1895 Copenhagen plates are now worth $4,000 apiece.

With a flash of commercial insight rivaling his father's genius, Rod realized that the worldwide exchange of these commemorative plates needed a reliable broker, someone to arrange purchases and sales and authenticate the items as well -- for a fee. In 1974, the Bradford Exchange was born.

Today, the Bradford Exchange acts as broker for almost every purchase and sale around the world, reports the fluctuating market prices of thousands of different decorative plates, and proselytizes among collectors and would-be collectors. There are an estimated 7.5 million plate collectors in the world, most of them in the United States and Western Europe.

The average sale price of a decorative plate is about $75. No great fortune to be made brokering that kind of transaction, but Bradford handles an average of 11,000 exchanges a day, and takes a 4 percent commission from the buyer for finding a seller, and a 30 percent commission from the seller. Every plate in a transaction is sent to the Exchange by the seller for inspection and authentication by Rod MacArthur's operation, which then sends the plate on to the buyer. The Bradford Exchange will gross close to $100 million this year.

In 1975, as Rod's brainchild was soaring, his father claimed the Bradford Exchange for his own. When the son demurred, the crusty old man, then 77, seized the exchange's customer lists and placed its major asset, 250,000 decorative plates, under lock and key.

Rod struck back: he organized a raid of John D.'s corporate headquarters in suburban Northbrook, where the plates were kept. John D. was caught off-guard in Florida, and while his employes protested helplessly, Rod's band hustled cartons of plates into their waiting fleet of trucks and drove off. He has never looked back. The Bradford Exchange here in Niles is now undergoing a major expansion.

A tinkerer and gadgeteer, Rod MacArthur several years ago bought Hammacher Schlemmer, the carriage trade gadget store in New York. Long unprofitable, it is now operating in the black.

MacArthur has also set up his own charitable foundation with about $23 million in assets. Named after him, it is known as the Little Mac to distinguish it from the gigantic Big Mac. Rod and his three children are the directors. The foundation has concerned itself with human rights, censorship, and social and sexual equality.

By 1978, when John D. died, father and son had reconciled. Rod and his stepmother were among the directors of the foundation set up under John D.'s will; most of the others were longtime business associates at Bankers Life, which became the foundation's principal asset. Rod's first skirmish came over his proposal to establish the MacArthur Fellowships. After a period of strain, the program was funded in 1981 with Rod as its director, and the first 21 fellows chosen. The unique program -- no application required, recipients selected without their knowledge by 100 anonymous nominators -- is Rod's doing.

But for years, Rod and the board have been split over a far more serious issue: that of divestiture. In the wake of revelations of self-dealing and tax-shelter abuses by foundations, Congress in 1969 passed a law requiring foundations to divest themselves of closely-held, for-profit assets. For the MacArthur Foundation, this meant the sale of Bankers Life, which is still being operated by John D. MacArthur's associates, and of most of the old man's real estate.

In a series of court filings and lawsuits in the past two years, Rod has accused the directors of costing the foundation millions of dollars by mismanaging both Bankers Life and its sale; paying themselves exorbitant fees; and seeking to mislead the Internal Revenue Service on the total value of the foundation. The officers and directors have denied the son's allegations. Rod MacArthur is pressing for a full-blown hearing in Cook County Circuit Court.

Despite the history of his own disagreements with his father, the sulfurous foundation situation and his own flagging strength, Rod MacArthur is determined to fight on.