Is the holocaust explicable?

In the discussions about the Holocaust, an increasing number of commentators - theologians, writers, as well as historians - argue that ultimately the Holocaust is a mystery, an inexplicable event in human history Various expressions are used, such as 'tremendum', with its theological connotations, or 'abyss', and many others. They all indicate a measure of final incomprehension that such a hornble event could have occurred in the midst of a supposedly civilized European society. Nazi atrocities are usually referred to as 'beastly', or 'bestiality', and very commonly as 'inhuman' The present paper tries to evaluate the explicability of the Holocaust from the standpoint of an historian.