David I. Kertzer

Pius IX became head of the Catholic church in 1846 and instituted the doctrine of Papal infallibility. Pulitzer Prize-winning author David Kertzer says his exile led to the emergence of modern Italy.

It's commonly thought that the Catholic Church fought heroically against the fascists in Italy. But in The Pope and Mussolini, historian David Kertzer says the church actually lent organizational strength and moral legitimacy to Mussolini's regime.

David Kertzer is the author of The Popes Against the Jews: The Vatican's Role in the Rise of Modern Anti-Semitism (Knopf). In the book he focuses on the time period from Napoleon to Hitler, and how "traditional" Catholic forms of dealing with Jews became transformed into modern anti-Semitism. Kertzer is Paul Dupee, Jr. University Professor of Social Science and a professor of anthropology and Italian Studies at Brown University.