PHILADELPHIA — Ralph Nader will deliver the keynote address, “Social Justice in the Post-Bush Era,” at the University of Pennsylvania School of Social Policy and Practice’s centennial celebration, Sept. 25 at 3 p.m. at the Zellerbach Theater at Penn.

Nader has spent 40 years advocating for change, exposing problems and helping create such public-interest agencies as the Consumer Product Safety Commission, the Occupational Safety and Health Administration and the Environmental Protection Agency.

Highlighting 100 years of social-work education at Penn, the School of Social Policy and Practice will have a year-long celebration, featuring special lectures, events, books about the school’s history and the formation of a new scholarship.

“For 100 years, the School of Social Policy and Practice has produced a generation of ‘thought leaders’ -- clinicians, agency leaders and policymakers,” Richard Gelles, dean, said. “Ralph Nader is an effective social-change agent –- and we are able to create social change because of the commitment of our students and our faculty, programs and research.”

Following the keynote address, there will be an alumni panel discussion, “Achieving Social Justice,” as well as a reception with light fare at 5 p.m.