Commencement keynote speaker David H. Souter '61 was one of ten recipients of honorary degrees from the University during the morning exercises on Thursday.

Souter, who is a 1966 graduate of Harvard Law School and served as an associate U.S. Supreme Court Justice for 19 years, received an honorary doctor of law degree.

Academy Award-winning actress Meryl Streep was presented with an honorary doctor of arts. Known for her versatility in front of the camera—playing both dramatic and comedic roles—Streep has garnered 16 Academy Award nominations and won two. She received her M.F.A. from the Yale School of Drama in 1975.

Minimalist sculptor and experimental video artist Richard Serra received a doctor of arts. Serra, who was hailed as “a titan of sculpture, one of the last great modernists" by The New York Times, has worked with splash pieces, prop pieces, and steel works. He studied painting at Yale.

Chemist Thomas R. Cech received an honorary doctor of science degree. A 1989 Nobel laureate in chemistry, Cech is currently the director of the Colorado Institute for Molecular Biotechnology at the University of Colorado. Cech's research served a pivotal role in the discovery that RNA can act as an enzyme—a function that had previously been viewed as exclusive to proteins. In 1987, Cech was elected to the U.S. National Academy of Sciences and was awarded a lifetime professorship by the American Cancer Society.

Biology professor Susan L. Lindquist was honored with a doctor of science. Lindquist, who received her Ph.D. in biology from Harvard in 1977 , teaches at MIT and focuses her research on complex molecular protein folding and the phenomenon's role in cancer, cystic fibrosis, and other diseases.

Harvard Medical School Pediatrics Professor David G. Nathan '51 received an honorary doctor of science. Nathan served as a physician-in-chief at the Children's Hospital and president of the Dana-Farber Cancer Institute. He is a 1955 graduate of the Medical School.

Philosopher Thomas Nagel was awarded an honorary doctor of laws. Nagel, who received his Ph.D. from Harvard in 1963 and studied under philosopher John Rawls, is currently a professor of philosophy and law at New York University.

Onora O'Neill, who was awarded a doctor of laws, was also a student of Rawls. The Northern Ireland native received her doctorate in philosophy at Harvard in 1969, and her philosophical work covers issues of trust, consent, and respect for autonomy in medical decision-making.

Educator Freeman A. Hrabowski III received an honorary doctor of law. He is the president of the University of Maryland, Baltimore County, where he co-founded the Meyerhoff Scholarship Program to increase the diversity of future leaders in science, technology, engineering, and related fields in 1988. In 2009, Time magazine named Hrabowski one of America’s 10 best college presidents.

Renée C. Fox, who received her doctorate in sociology from Harvard in 1954, received an honorary doctor of law. Fox was a visiting lecturer at Harvard's social relations department before joining the University of Pennsylvania's sociology department.

—Staff writer Xi Yu can be reached at xyu@college.harvard.edu.