On 24 August 1941, Hitler ordered an end to the first phase of adult euthanasia. He gave this order to Karl Brandt, who transmitted it to the KdF.1 Popular history and special pleading have credited opposition by the churches with this abrogation of the killing operation. But Hitler was probably pushed to issue his so-called stop order primarily by widespread public knowledge about the killings and far less by church opposition, an opposition that merely reflected general popular disquiet about the way euthanasia was implemented.2 The Protestant (Lutheran) and (Roman) Catholic churches were, in any event, ambivalent toward Nazi health care policies, including sterilization and euthanasia, and their resistance could have been overcome.3 In the same way, opposition from the judiciary, which also reflected popular disquiet, had been quietly settled before the stop order.
Public knowledge and popular disquiet were thus the principal reasons for Hitler's decision. In 1940 public knowledge and discontent had led Himmler to suggest the closing of Grafeneck; the same reasons led Hitler to issue his order in August 1941. By the summer of 1941, the secret of the euthanasia killings had become public knowledge and was even known in neutral countries as well as in the nations fighting against Germany.4 In any case, Hitler's stop order was only a tactical retreat. Children's euthanasia, for example, continued without interruption.5 And as we shall see, the stop order did not end adult euthanasia; in the second phase, it resumed with great intensity but out of public view. Further, we shall see that some of the killing centers subsequently murdered other victims and that the T4 killing personnel moved to the East for larger tasks.
As killing operations expanded to include Jews and Gypsies, the experiences of euthanasia forced the killers to change their procedures. They transferred the killing arena to the East. To limit opposition from close relatives, an opposition that had vexed the killing operation against the handicapped, they deported not individual Jews and Gypsies but entire nuclear families, did not deport Jews living in mixed marriages unless the non-Jewish relatives had died, and even in Auschwitz usually sent healthy young mothers to the gas chamber with their young children while those without children were often selected for labor. At the same time, jurisdictional disputes were revived. In 1939 the KdF had persuaded Hitler to entrust it with the first killing operation, and Leonardo Conti at the RMdI and Reinhard Heydrich at the RSHA