This correspondence between Merton Gill, M.D., and Philip M. Bromberg, Ph.D., includes five letters written between December 7, 1979, and January 8, 1984. The first letter, from Gill to Bromberg, shared reflections on Bromberg's paper “Interpersonal Psychoanalysis and Regression,” published in the October 1979 issue of Contemporary Psychoanalysis. The exchange of letters that follows takes up a number of issues relevant to the evolution of analytic theory and technique, of historical as well as contemporary interest. Their discussion moves from a consideration of the nature and role of regression in psychoanalytic work to a consideration of mental structure and mental states, to free association and the analysis of transference, and finally to their reflections on the analytic frame and analytic technique itself.