From 1972 to 1989, he was Lecturer, then Reader, at the Science Studies Unit, University of Edinburgh, and, from 1989 to 2003, Professor of Sociology at the University of California, San Diego, before taking up an appointment at the Department of the History of Science at Harvard.
He occupied academic positions as Lecturer, Reader, and Professor of Sociology at the University of Edinburgh (1972-1989) and then Professor of Sociology at the University of California, San Diego (1989-2003), before joining Harvard's Department of the History of Science.