In a nutshell they could be viewed as two sides of the same coin.

Both argued, Browning's book first followed by Goldhagen's, that most of those involved in the Holocaust, such as the bureaucrats and the killing squads, were 'ordinary men'. Drawn from all parts of German society, few with any unique proclivities towards violence, and all essentially willing, if not always initially, to be involved in the horrific acts that were perpetrated.

Where they disagree is what drove people to commit these crimes. Goldhagen argued, in response to Browning's book, that Germans willingly took part in these acts because of a unique 'eliminationist anti-Semitism', innate to the German people since Luther's polemics on the subject in the 16th century. Hitler represented the climax of German history (echoing the Sonderweg thesis), fulfilling the dreams of the German people that the Jews might be exterminated. When Hitler gave them the opportunity to partake, ordinary Germans were trampling each other to get in on the action.

Browning argued differently. Rather than seeking one cause, he emphasized a variety of factors that influenced people. In the case of Reserve Police Battalion 101, he found that these men were mostly average, middle aged German men, largely from Hamburg. They were not extensively indoctrinated, nor were they terribly receptive to that which they received. Some were initially anxious, even uneasy, with the task they were set out to do; but they carried it out nonetheless.

They described how they feared being viewed as weak by their peers, as not being able to do the tough job they were given. Alcoholism was extensive, consumption before or after killings being common; alcohol does desensitize, so it served as a coping mechanism, CLEARLY demonstrating that these men were not subconscious, rampant anti-Semites, but 'Ordinary Men'. The more they killed, the more routine and less exceptional these acts became, leading the killings to become almost 'banal'. They killed both Poles AND Jews, so they were clearly not solely driven to kill by a hatred of Jews.

Goldhagen's thesis is deeply flawed, and has been attacked and largely dismantled by historians and psychologists. Notably Raul Hilberg, practically the godfather of Holocaust Studies, dismissed 'Hitler's Willing Executioners' as 'totally wrong'.

Suffice to say, no matter what 'side' you 'take', it doesn't change just how horrific the Holocaust was; nor the even more terrifying fact that most, if not all, of those 'willing executioners' were 'ordinary men'. That's what scares me the most.