By all rights, Donald Hopkins should be a household name. The Bahamian-American physician and special adviser to the Carter Center is one of the key individuals responsible for the eradication of smallpox—a truly terrifying disease that in the 20th century alone killed as many as 300 million people. Hopkins then turned his sights to eliminating Guinea worm disease, a painful ailment that once plagued millions in Africa and Asia. He’s now 76 years old and still focused on purging the parasite-driven illness from the two countries, Ethiopia and Chad, where transmission persists—a task to which he’s bringing both a mastery of public health and a lifetime’s worth of understanding political intransigence and apathy.
The Guinea worm challenge is the kind of “impossible” mission tailor-made for someone like Donald Hopkins, one of Fortune’s 2018 “World’s 50 Greatest Leaders.” But as the good doctor tells Fortune’s Erika Fry, there is another infectious disease that’s even more dangerous to humanity—and that’s the “failure of imagination.”
It’s an insight that, through a kaleidoscope of different achievements and life experiences, resurfaces many times in this year’s list—our fifth annual roster of imagination-embracing game changers, paradigm shifters, and unsung champions across multiple fields of endeavor. FDA commissioner Scott Gottlieb seemed to draw from a whole new regulatory playbook when he recently proposed a policy shift that could eventually reduce the amount of nicotine in cigarettes to the point where they were no longer addictive. The notion is shockingly straightforward—and it could save countless lives.
SpaceX’s Gwynne Shotwell has used such creative problem solving to turn the Mars-eyed ambitions of her boss, Elon Musk, into actual Earth-departing rocket ships. Balkrishna Doshi has reimagined architectural design for the masses, conceiving of homes for a community of tens of thousands of people that still feel lush with open spaces. Black Panther director Ryan Coogler foresaw a cinematic world that broke Hollywood traditions as it broke box-office records too. Led by its imaginative CEO, Mary Barra, GM quietly guided its electric Chevrolet Bolt EV into the market before Tesla’s Model 3 could push its nonexistent start button. And Salesforce boss Marc Benioff and actor/producer Reese Witherspoon each decided that wanting pay parity for women and men wasn’t enough. So they just, well, made it happen in their own domains—offering a real-world lesson to anyone who claims that such equity is too hard to accomplish.
Perhaps most remarkable is the collective imagination of students across the United States, who dared to take on a challenge that their parents, aunts, and uncles had all but abandoned: stopping the scourge of gun violence.
On a list like ours, it’s easy to get lost in the politics—the pinpointing of causes on a spectrum of left to right, blue to red, black to white, male to female. But that’s not the point of our annual exercise. Whatever the mission, we simply looked for people who had proved to be great at leading it.
As always, I hope you’ll write and let us know which of our choices you agree with—or don’t. In the meantime, I believe we can all learn something powerful from each of them.
Donald Hopkins was only 26 when he arrived in Sierra Leone to begin inoculating millions of people against the smallpox virus. No disease had ever been eradicated before—but Hopkins wasn’t fazed. “We were young and naturally optimistic,” he says.
That’s something that a good leader never outgrows.
This article first appeared in the May 1, 2018 issue of Fortune magazine.