Fifty years after the founding of the Peace Corps, Sen. Benjamin L. Cardin urged 6,400 graduates of the University of Pittsburgh to lead a life of service.

“Don’t just see the light,” he said. “Be the light.”

Cardin, 67 and a 1964 Pitt graduate and admirer of the Peace Corps, delivered the commencement address before 13,700 people on Sunday at the Petersen Events Center in Oakland. He was awarded an honorary doctorate of public and international affairs from the university.

He was elected to the U.S. House of Representatives in Maryland in 1986 and to the Senate in 2006. He serves on the Senate Finance Committee and the U.S. Helsinki Commission.

Citing Martin Luther King, Jr., Cardin asked the graduates to heed the inner voice that urges them to do something for the greater good.

“Everybody can be great,” the civil rights leader once said, “because anybody can serve.”

Cardin recalled a Peace Corps volunteer he met in Morocco. She was teaching women how to be entrepreneurs so they could make a fair living from their work as artists.

“The Peace Corp captures the essence of our country at its best — highlighting America’s strengths and demonstrating that each of us can make a difference,” he said.

The students wore black caps and gowns and colorful hoods symbolic of the various schools within the university. As their school’s name was called out, the graduates cheered and showered confetti and streamers.

Despite the hoopla, some graduates harbored a mix of caution and optimism about the future.

“I’m very hopeful,” said Alexis Wilder, 21, of Phoenix. “I’m the first in my family to graduate from college, so I already accomplished a lot.”

Wilder received a bachelor’s degree in psychology and hopes to go to graduate school at Arizona State University.

Sarah Anderson, 21, of Shamong, N.J., took the occasion to reflect on the progress of women. After getting a bachelor’s degree in urban studies and environmental studies, she hopes to get a job planting trees.

“The American dream for women used to be graduate from high school, get married, have kids,” she said. “But now it’s graduate from high school, graduate from college, get a job, have your own thing and get married whenever you feel like it.”

Demitri Mallios, 21, of Mechanicsburg, Cumberland County, picked up a bachelor’s degree in neuroscience and is on the waiting list for Pitt’s medical school.

“Sure, things could look bleak,” he said. “But without the future, we have nothing.”