"No one should assume that a life of reason is easy," she said. "To the contrary, it takes a great deal of courage and honesty - for the only way you're going to grow intellectually is by examining your opinions."
She told the graduates to reject "false pride," and to not take their new degrees for granted. She said there are plenty of people as intelligent and deserving of the education they were given, but "for whatever reason - maybe a broken home, poverty or just bad luck - these people did not enjoy the opportunity that you have had at Johnson C. Smith."
She told them to be optimists and continue the work to "advance progress."
Rice, 55, grew up in segregated Birmingham, Ala., at a time when African-Americans found it difficult to aspire. "Differences have been used to divide and dehumanize," she said.
She'd wanted to be a concert pianist, but in college at the University of Denver, she found she didn't have what it takes to "make it to Carnegie Hall."
Instead, she said her passion became all things Russian - finding it in a international politics class taught by the father of Madeleine Albright, the country's 64th secretary of state.
Years later, escorting Soviet leader Mikhail Gorbachev to California with President George H.W. Bush, she was glad she found that passion.
"Your passion may be hard to spot," she told the graduates. "But keep an open mind and keep searching."
Rice knows JCSU
JCSU President Ron Carter had little trouble persuading Rice to address the school's 138th commencement.
She knows the west Charlotte school well.
Her father, the late Rev. John Wesley Rice, graduated from there with a history degree in 1946 and a doctor of divinity two years later. He became a Presbyterian minister and football coach.
As age 11, she visited the campus when her father attended a meeting of Presbyterian ministers. Bored, her mother let her explore.
Rice returned in 2004 to give the convocation speech.
Sunday, she told the graduates: "Johnson C. Smith University has made a lot of progress, but I think it's kept the same heart and soul."
Under a warm, cloud-draped sky, the procession was led into the school's football stadium by African drummers and stilt dancers.
Before Rice spoke, President Ron Carter presented her with the school's honorary doctor of laws degree. Leonard Haynes, an educator who headed up a White House initiative on historically black universities and colleges from 2007 to 2009, was given a doctor of humane letters degree.
'Prove them wrong!'
Jason Stuckey, a JCSU tennis player, was the valedictorian. Nikki Boston, another Smith athlete, was salutatorian.
Stuckey said some graduates might hear that a JCSU degree isn't good enough. He urged his classmates to: "Prove them wrong!"
Rice agreed, invoking the lessons of her ancestors.
"Because of what all my ancestors endured, including poverty and segregation, they understood that education was a privilege," she said, "But that privilege brings obligation... It is your responsibility as educated people to reject prejudices and help close the gap of injustices and opportunities that still divide our nation and our world."