German philosopher whose writings played a role in the emergence of the German existential movement. Neither an idealist nor a constructivist, as were his contemporaries, he believed philosophy's role was to seek “faith” through understanding rather than religious spirituality or scientific experimentation.

Frank studied linguistic origins and classics at the universities of Vienna, Freiburg, and Berlin before moving to the University of Heidelberg (1907–10), where he explored philosophy under Heinrich Rickert and Wilhelm Windelband and where he later became a professor (1923–28). After dismissal from his appointment at Marburg (1928–35), he conducted research at Harvard University (1939–48) emphasizing the interweaving of history and philosophy. He eventually became a U.S. citizen and, in his final year, taught at the University of Pennsylvania. His principal works include Plato und die sogenannten Pythagoreer (1923; “Plato and the So-called Pythagoreans”), Philosophical Understanding and Religious Truth (1945), and Wissen, Wollen, Glauben (1955; “Knowledge, Will, Belief ”).