When Campbell Soup (CPB) CEO Denise Morrison told the company’s directors a few years ago that she wanted to buy Bolthouse Farms, which sells packaged carrots, salad dressing, and premium beverages, she had to sell them on it. Morrison knew that the $1.55 billion acquisition would help her company diversify into new types of packaged food.

“The board said, ‘Carrots, Denise? Really?’ said Morrison. “I said, ‘No, package fresh!'”

The board went along. But to Morrison the moment was about more than just making a smart strategic move. It was about demonstrating “leadership courage” and pushing her very traditional company to get more comfortable with risk. Campbell’s three best-selling products—tomato, mushroom, and chicken noodle soup—are all decades old.

“I was dealing with risk adversity,” said Morrison. She felt it was critical to reshape the culture at Campbell’s to get comfortable with failure. “It’s okay to fail if you learn from it.”

That sentiment is accepted wisdom in Silicon Valley, where “failing fast” is such a widely embraced management precept that it has reached the point of cliché. But it’s a lesson still being learned by some of the Fortune 500’s most venerable companies.

Morrison told the acquisition story at Fortune‘s Global Forum conference in San Francisco on Tuesday during a panel discussion alongside the top executives of two other extremely mature companies: German engineering giant Siemens and defense contractor Lockheed Martin (LMT). The theme of the conversation was how aging corporations can stay relevant in a world where the pace of change appears to be speeding up. Consider the fact that early in the last century the average age of a company on the S&P 500 was 90 years old; today the average age is under 20.

Between them, Campbell’s (146 years old), Siemens (168), and Lockheed Martin (103) have been in existence for a total of 417 years. The CEOs of all three companies said in varying forms that staying relevant and competitive came down to motivating employees by building a culture based on corporate purpose.

Siemens CEO Joe Kaeser said that his company was transforming rapidly. “Fifty percent of our business has changed in the last 10 years,” he said, as the Internet transforms the needs of customers in ways both big and small. The key to succeeding in such an environment, said Kaeser, is to have an ownership culture. Financial incentives aren’t enough. “You have to get to people’s hearts. You have to get to people’s pride.” But it’s also good for workers to have a real stake. Some 144,000 out of the company’s more than 340,000 employees own shares in Siemens, and Kaeser said the number was on the rise.

Pushing his company to be socially responsibility has also resonated with would-be employees, said Kaeser. Siemens recently said that it would be carbon neutral by 2030, and Kaeser said the company was immediately flooded with resumes from new applicants. “I was surprised myself,” he said.

Lockheed CEO Marillyn Hewson said that her company is able to attract talent by taking on ambitious technology challenges, such as designing the Orion deep-space exploration spacecraft for NASA, which may be used to send a manned mission to Mars some day. “Ours is about a culture of innovation,” she said. “People come to our company because they want to work on the things we do.”

Campbell Soup’s Morrison is keeping her focus on decidedly more earthly matters, such as winning the loyalty of millennials with healthier food and preparing for a world in which more and more grocery purchases are made online rather than in stores. “For me it’s about starting with the consumer and understanding the seismic shifts,” said Morrison. And having the courage to take some chances.