As an explanation for 
entrepreneurial success, the vision thing has been taking its lumps lately. Great ideas are a dime a dozen, goes the argument; what's scarce is people who can execute on them. While the importance of execution is indisputable, a string of conversations we've had recently at Inc. has reminded us all that greatness always, always starts with the idea--or, to be precise, an idea backed by ferocious belief.

On the stage of Inc.'s Women's Summit, we hosted the great Sara Blakely, founder of Spanx and the youngest self-made female billionaire in history. Spanx's origin story is famous--Blakely cut the feet off pantyhose and improvised a slimming product that solved a problem 
for women everywhere. The idea was simple, effective, and brilliant, but it would have died in Blakely's Atlanta kitchen had she not followed it up by phoning, then visiting, every hosiery mill in North Carolina, until her conviction overwhelmed the skepticism she met in all quarters and she found a manufacturing partner.

Two days later, on the stage of our Los Angeles iConic conference, the founders of Zumba Fitness made a similar point. You may know their startup story, too: how Alberto Perez, the company's creative force, and Alberto Perlman, the CEO, met at the urging of Perlman's mother to discuss Perez's idea for a business that made fitness fun. After 
the two agreed that they loved the concept, Perez asked, "Do you have any money?" "No. Do you?" "No." Perfect, the two agreed--what could possibly go wrong?

What I hadn't heard before was this: At the time of 
the meeting, Perez already had a lead on a million dollars in funding. Why did he turn instead to the penniless Perlman? "Something in here," he says, pointing toward his well-muscled chest, "told me that he was the partner I was looking for." So, success lesson number one: 
Listen to your heart. Number two: Listen to your mom.

In the issue you're holding, you'll find still other stories of world-changing vision backed by fierce conviction. As San Francisco bureau chief Jeff Bercovici relates in our cover feature, Memphis Meats co-founder Uma Valeti left a comfortable career in cardiology to pursue the idea of growing real meat in the laboratory. He remains a long way from a commercial product. What holds the company together is incremental progress and Valeti's belief that the idea will work--that, indeed, it must work, to save the planet.

The same mix of science and conviction is central to editor-at-large Kimberly Weisul's feature about Saundra Pelletier, CEO of Evofem, maker of a breakthrough contraceptive gel. Pelletier and her company are caught in the regulatory mire known to every company trying to introduce an innovative medicine. While FDA clinical trials proceed glacially, Pelletier is holding her company together by force of will. There is no guarantee Evofem will succeed. But there would have been no chance at all without Pelletier's vision.