I haven't commented yet on this article in which the Vatican's chief exorcist is reported to have stated that Hitler and Stalin were possessed by the devil (or a demon).

At one point in college, when I thought I knew a lot more than I think I do now, I had decided that angels and demons were superfluous to explain the universe, probably mythic explanations for things such as self-destructive human sinfulness, and the ability of a transcendent God to interact with the universe. Two things changed my mind: first, probably from my background in science, I remembered that we can determine what exists in the universe only by experience and observation, not by a priori decision; second, a passage in the theologian John Macquarrie (no conservative) to the effect that it is rather egotistical of humans to suppose themselves alone with God in the material universe. As C.S. Lewis observed, belief in devils is not required of Christians--it's not in the Creed--but it is the plain reading of Scripture, the belief of the Church through the ages, and indeed the belief of most people of most cultures of human history.

For a time, in college again, I resumed belief in demons (and angels) but refused to believe in demon possession. To me it seemed that human perversity and sinfulness could explain all that needed to be explained regarding sin and sinful behavior. But, alas for my hypothesis, the same reasoning given above that moved me back to belief in demons also applied to demon possession--it is the plain reading of Scripture, the Church through the ages has believed in possession, and indeed most human cultures have beliefs in similar things. And, reality is not known a priori, but by observing what is. Also, though I won't discuss it now, I've observed more. (more below)

It seems to me there are two pitfalls regarding belief in demon possession. On the one hand, I do not explain all human bad actions as consequence of demon possession. This, to my thinking, is part of the bad theology of the Perritti books such as This Present Darkness. As a Calvinist I stress the perverse power of human sinfulness. On the other hand, for the reasons given above, I think it is a mistake to disbelieve in demon possession.

Were Hitler and Stalin possessed? It does seem that their evil deeds, and personalities possess an almost supra-human quality. I am reminded of something someone remarked who knew more of Hitler's life than I do : "Hitler's behavior when angry or frustrated would have caused people of another age to think him possessed."