These six letters, drawn from the unpublished correspondence between Sigmund Freud and Sándor Ferenczi, were written in the 1920's. Ten years previously, Freud had published his famous papers on technique in which he formulated the basic tenets of the classical procedure. Ferenczi, after the end of the First World War, attempted to develop new technical measures for the treatment of pregenitally disturbed patients who were unable to associate freely. The so-called 'active technique' and 'relaxation therapy' were the two techniques he developed successively and, for a time, pushed to extremes. In the letters Freud is both encouraging and critical.—The commentary describes the biographical and historical background and draws a connexion between Ferenczi's technical experiments and his prematurely terminated training analysis with Freud. It also becomes apparent that Ferenczi was the first systematic investigator of severe ego-pathologies and their treatment and further, that his work, directly and indirectly, has exerted a great influence of more recent psychoanalysis.