''Euthanasia,'' in its Greek derivation, means ''good death.'' The word is generally used for actions taken to facilitate the deaths of those who are already dying, and has long been a subject of debate for physicians, moral philosophers and the general public.

The Nazis, however, used the term ''euthanasia'' to camouflage mass murder. Just how the Nazis were able to do that has been made clearer by recent historical research and by interviews I was able to conduct during the last decade with German doctors who participated in the killing project.

Nazi medicalized killing provided both the method - the gas chamber - and much of the personnel for the death camps themselves. In Auschwitz, for instance, doctors selected prisoners for death, supervised the killings in the gas chambers and decided when the victims were dead.