Clinton was welcomed to Chicago by old political friends, with an introduction by the current Mayor of Chicago Rahm Emanuel brought him to the stage for the opening dinner of the World Summit of Nobel Peace Prize Laureates.
He urged all those listening to be agents for positive change and set good examples.
"You also have to find a way to step into the gap between where we are and where we ought to be," Clinton said.
The dinner capped the first full day of Summit activities and discussions, concerns about the current challenges for peace and investing in peace.
Much of the message was made to a new generation of human rights defenders.
"The real story isn't the repression but the resistance, not the terror, but courage, not the futility, but the power of one," Kerry Kennedy said.
"Look at the Nobel laureates lives and say, 'how can I contribute to make peoples' lives more peaceful and let all aspects of human rights prevail?'" Carter said.
Earlier in the day, some participants visited Chicago Public Schools.
Former Soviet President Mikhail Gorbachev answered students' questions, along with Sean Penn, who is being recognized at the Summit for his work in Haiti.
"Now we have 12,000 employees," Penn said. "We work principally in engineering in ruble removal, demolition, two hospitals and education."