At Tuesday evening’s sophomore convocation, one of the main speakers was noticeably absent.

Dan Ariely—James B. Duke professor of psychology and behavioral economics—was replaced by Ingrid Byerly, senior lecturing fellow in cultural anthropology, who was asked to speak at the ceremony only a few hours before addressing about 200 members of the sophomore class in Cameron Indoor Stadium. Ariely had originally been told that the event was starting at 8 a.m. instead of 8 p.m., which is why he was unable to attend.

"They told me to be there at 8 a.m. for this, and I was there at 8 a.m.," Ariely wrote in an email Wednesday morning. "Later they told me that it was a mistake and the right time was 8 p.m. but my class was going on at that time—so I could not make it."

The Sophomore Class Council-sponsored event also featured an address from Mark Anthony Neal, professor of African and African American studies. The two speakers emphasized balancing students’ achievements with concern for a broader community.

“You are expected to be the leadership of this [generation] at this moment,” Neal said. “I’m not telling you that you shouldn’t live the good life. The good life is a worthy goal. But don’t let it keep you from being accountable to larger forces in our society you are being trained to address.”

Neal's speech invoked tennis stars Venus and Serena Williams as examples of individuals who stayed grounded in their communities, encouraging students to do the same.

“Part of what’s so important to remember is the humility that’s associated with [greatness]. Who are you protecting, who are you responsible to?” Neal said.

Byerly, who is from South Africa, referenced Nelson Mandela’s life and advice in her speech, calling for students to think beyond themselves.

“If you wish others to remember your name, you must remember theirs first,” she said. “If you want the world to be a better place, you must find a cause before it finds you. Think about what is important even if it hasn’t affected you.”

Byerly brought her public speaking class to critique her address, noting that Duke basketball player Grayson Allen, a sophomore, was in her class and would have been in attendance were it not for the basketball team’s invitation to the White House Tuesday.

Sophomore Alex Hong did not seem fazed by Byerly’s unexplained substitution for Ariely.

“I thought, given that Professor Byerly didn’t have much time, that it was a pretty good presentation,” Hong said. “It was inspiring and true. I feel grounded.”

Byerly and Neal made up for Ariely’s absence, said sophomore Vanessa Lusa, adding that she was “pleasantly surprised.”

Sophomore Class President Luke Duchemin closed the event, noting that this year the Sophomore Class Council will be supporting students and organizations interested in “authenticity.” He also encouraged those in attendance to spread Neal’s and Byerly’s message to the rest of the class.

“You’ve got 1,600 other people you’re going to have to push and inspire because they weren’t here tonight,” he said.

Samantha Neal contributed reporting.

Update: This story was updated at 11:30 a.m. Wednesday to include Ariely's comment.