B.A. in physics from New York University, 1940; graduate work at University of California at Berkeley; contacts with J. Robert Oppenheimer at Berkeley and Princeton University; move to industrial physics and Bell Labs; re-entered university life at University of Wisconsin; developed University of California Santa Barbara's Institute for Theoretical Physics. Majority of interview devoted to JASON: motivation for joining; chairmanship of JASON during Vietnam involvement; selection of projects; important projects; technical advice versus policy advice; impact of JASON.