Why did practices like foot binding, dueling and slavery come to an end? How do societies start to reject immoral customs that they have long accepted as part of their culture?

Eminent philosopher, cultural theorist and novelist Kwame Anthony Appiah, one of Foreign Policy magazine's Top 100 Global Thinkers, will explore those questions -- and offer answers -- as the Cornell University Graduate School's 2011 Spencer T. and Ann W. Olin lecturer Friday, Sept. 23, at 7:30 p.m., in the Alice Statler Auditorium in Statler Hall.

Appiah will base his lecture on his most recent book, "The Honor Code: How Moral Revolutions Happen," one of The New York Times' 100 Most Notable Books of 2010.

Appiah will discuss how honor is the engine behind moral progress. Reason, morality and religion, he says, aren't enough to ring in reform. Practices are eradicated only when they come into conflict with the need for respect from one's peers, he says.

"While based on history, Appiah's ideas have a potentially electrifying application to the present," says Barbara A. Knuth, vice provost and dean of the Graduate School. "His work could offer a path to a better future by showing how mobilization of a sense of collective honor -- and shame -- can motivate us to do the right thing in cases where our baser instincts have prevailed."

Appiah was born in England, raised in Ghana and educated at Cambridge University. Trained in probabilistic semantics, he is best known for his work on questions of race, religion, multiculturalism and identity.

He has published widely in African and African-American literary and cultural studies and co-edited the "The Dictionary of Global Culture" with Henry Louis Gates Jr. Appiah is the author of three novels and regularly reviews for The New York Review of Books. In 2009 Forbes Magazine named him one of the world's seven most powerful thinkers.

Appiah has served on the faculties of Cornell, Duke, Harvard and Yale universities; currently, he is a philosophy professor and director of the University Center for Human Values at Princeton.

Tickets for the lecture are free and available to the public at 350 Caldwell Hall, the Willard Straight Hall ticket office, Ticket Center Ithaca and Buffalo Street Books. For ticket information or to request special accommodations, call 607-255-5810.

"The Honor Code" will be available for purchase at the Cornell Store and at the lecture. Appiah will sign copies during a reception immediately following his lecture in the Statler's Beck Center Atrium.

The Spencer T. and Ann W. Olin Fellowship Program -- of which this annual lecture is a part -- was established at Cornell in 1987 to foster the intellectual exchange of ideas and help drive discussion of critical issues in the sciences and the humanities. The lecture is part of an ongoing series.