Gerald J. Holton is an American physicist, historian of science, and educator, whose professional interests also include philosophy of science and the fostering of careers of young men and women. He is Mallinckrodt Professor of Physics and Professor of the History of Science Emeritus at Harvard University. His contributions range from physical science and its history to their professional and public understanding, from studies on gender problems and ethics in science careers to those on the role of immigrants. These have been acknowledged by an unusually wide spectrum of appointments and honors, from physics to initiatives in education and other national, societal issues, to contributions for which he was selected, as the first scientist, to give the tenth annual Jefferson Lecture that the