• Assistant (1927), Privatdocent in Classics (1932), Frederick William University of Berlin, 1927–1933 • Lecturer in Greek Philosophy,
University of Rome, 1933–1938 • Lecturer in Mediaeval Philosophy (Arabic and Hebrew) (1942), Senior Lecturer in Arabic and Greek Philosophy (1950),
Oriel College, Oxford, 1942–1962 • Honorary Professor, University of Hamburg, 1952 • Member,
Institute for Advanced Study,
Princeton, New Jersey, 1953–1954 • Fellow, Reader in Arabic and Greek Philosophy
St Catherine's College, Oxford, 1962–1970 • He was elected a Fellow of the
British Academy in 1956. ==Publications==