University officials said they are saddened by Appiah’s departure.

“Professor Appiah is a wonderful scholar and a good personal friend, and I am very sorry to lose such a splendid colleague. Both personally and as Dean, I shall miss him greatly,” FAS Dean Jeremy R. Knowles wrote in an e-mail.

“Professor Appiah has made important contributions at Harvard through his work in African American Studies and in Philosophy,” Summers wrote in a statement. “We wish him every success in the future.”

Appiah will remain at Harvard for the spring semester.

According to his colleagues in the Afro-American studies department, Appiah’s departure will be a huge loss.

“Anthony Appiah is irreplaceable,” Gates said. “He is the most brilliant philosopher of Afro-American studies at work today.”

But Appiah said yesterday that the Afro-American studies department would remain strong—even if Gates and West follow his exit.

“Suppose all the people in question left,” he said. “This would still be the best collection of African-Americanists in the world.”

The arrival of Michael C. Dawson—said to be the world’s foremost black political scientist—this summer should also bolster the ranks of the department, as will two new senior appointments and two junior appointments scheduled to begin at the beginning of the next academic year.

—Juliet J. Chung contributed to the reporting of this article.

—Staff writer Kate L. Rakoczy can be reached at rakoczy@fas.harvard.edu.