MacArthur’s son, John Roderick MacArthur (known as Rod), was also on the board. His legendary fights with Kirby and other board members turned early meetings into roiling, contentious knuckle bruisers. But this time the two were in agreement: In an amazing bit of cooperation, MacArthur and Kirby would share the credit for making an expansive idea of no-strings grants a reality. As Rod MacArthur explained in interviews, he wanted to free “genius” from “the bureaucratic pettiness of academe.” These grants would go to individuals, not institutions. “Albert Einstein could not have written a grant application saying he was going to discover the theory of relativity,” he said.

The first 21 MacArthur fellowships were announced in June 1981. The winners would receive, among other things, “the gift of time,” wrote Denise Shekerjian in her 1990 book, Uncommon Genius. Although the fellowships these days account for only about 5 percent of the foundation’s annual grants, they are by far the best-known of its programs.

By the end of his life, John MacArthur had mellowed a bit about what would happen after he was no longer able to call all the shots. There was no point trying to run things from the grave, he told a reporter. “You have changing times. Besides, you lay down rules and people don’t follow them. So I’ll trust to the Almighty that my trustees will do more good for the country than I would.”

Some critics charge that the foundation has funded more liberal social activism — even in its selection of fellows — than the archconservative who made the money would have tolerated. But who knows? MacArthur’s life was almost as rich in paradox as it was in dollars.

Nancy Kriplen is the author of “The Eccentric Billionaire: John D. MacArthur — Empire Builder, Reluctant Philanthropist, Relentless.” Adversary.”