David M. Kelley — American Businessman

David M. Kelley is an American businessman, entrepreneur, designer, engineer, and teacher. He is founder, chairman, and managing partner of the design firm IDEO and a professor at Stanford University. He has received several honors for his contributions to design and design education... (wikipedia)

I always found that if you handle a problem in a benevolent way and a transparent way and involve other people, so it's just not your personal opinion, that people get to the other side of these difficult conversations being more enthusiastic.
The main tenet of design thinking is empathy for the people you're trying to design for. Leadership is exactly the same thing - building empathy for the people that you're entrusted to help.
When I was in high school, I lettered in math. The only thing that was important was football. There were two other letters that were awarded each year. One was in math and one was in science. I got the math one. But you didn't put it on a letter sweater and wear it around because they'd be throwing you in a wastebasket upside down on your head.
The profession of being a creative thinker is not so obvious.
The way I would measure leadership is this: of the people that are working with me, how many wake up in the morning thinking that the company is theirs?