Gen. Colin Powell believes there's a distinct difference between the science of management and the art of leadership.
The bridge from one to the other, he said in South Barrington Thursday, is vision and the ability to share it with one's followers.
Powell is headlining Willow Creek Community Church's annual Global Leadership Summit, which runs through Friday afternoon.
Eight thousand attendees were on the church's South Barrington campus Thursday to hear Powell's reflections on leadership. Many times more were tuning in from remote locations around the world.
He shared stories of how his life's experiences shaped his view on leadership, and took direct questions from Willow Creek Senior Pastor Bill Hybels.
Hybels particularly wanted to know if racism had been a barrier to any of Powell's goals, or his life as a leader.
Powell said he couldn't deny having seen the effects of racism in America, but that he was fortunate to have lived at a time when that America began changing.
He also benefitted from a career in what he considers the most socially progressive organization in the nation -- the military.
The military has always been good at spotting problems and working to fix them -- even if that problem is racism's interference with its ability to function well, he said.
Though aware that others may have seen his promotions as some form of affirmative action, Powell said he knew that was their problem to deal with and his was to be the best officer he could be.
And even though America has now elected a black president twice, Powell said the nation mustn't be blind to the fact that not every member of a minority has benefitted from changing attitudes.
"As we move forward, let's not leave anyone behind," he said.
Powell believes his brand of leadership recognizes that it's the people he's leading who are actually doing the work. He's always felt it important to make sure everyone knows their importance to a particular organization -- including the woman who cleaned his office when he was Secretary of State.
Even in the military, he says, he never relied on, "That's an order!" to get things done.
Americans are brought up with an expectation of knowing how their actions are contributing to society's goals, Powell said.
"There's no unimportant person in an organization," he added. "You have to invest in followers and give them what they need to get the job done."
The key asset a leader should have is perpetual optimism, Powell said. There's no way to make a group of human beings more powerful than through a continuous display of optimism in their and the organization's ability, he said.
On the flip side, the biggest red flag he saw among the world leaders he met is ego. Without humility or consideration of others, they are missing the most important ingredient of true leadership, Powell said.
Many other leaders from various disciplines, including popular TV producer Mark Burnett ("Survivor," "Celebrity Apprentice," "The Voice," "The Bible," "Shark Tank") will share their insights throughout the rest of Willow Creek's summit.