Hoffman is a historian of German, European and International History from the late 18th century to the present. He also has an ongoing interest in social, legal and political thought, as well as in the theory of history.
His most recent book is an intellectual biography of Reinhart Koselleck and an exploration of his premise that 20th-century experiences of time require a new theory of history. Currently, he is working on two research projects: a book-length essay on human rights internationalism from imperial beginnings to our global present, and a monograph on everyday life in Berlin in the 1940s, as it went from multinational capital of the Nazi Empire to shattered metropolis of the early Cold War. His previous two books traced the afterlives of Enlightenment concepts and social practices (sociability, cosmopolitanism) in the long 19th century and their late 20th-century resurgence. Together with Samuel Moyn, he is the editor of the Cambridge series Human Rights in History.
His writings appear simultaneously in German and English on both sides of the Atlantic and have been translated into several other languages. At Berkeley, he is affiliated with the Institute for European Studies; the Pacific Regional Office of the German Historical Institute; the Institute for Slavic, East European and Eurasian Studies; the Institute for International Studies; the Department of Rhetoric; the Department of German; and The Program in Critical Theory.