This entry was originally titled, "Would you kill Baby Hitler?" Unfortunately, as several readers pointed out, most of the comments centered on the title, suggesting few had made it to the end. The entry is not about Hitler so much as about fate, chance, and luck. I'm giving it a second chance under another title.
The original entry began: Of course, you would have needed to know on April 20, 1889 that the little boy would grow up to become Adolf Hitler, and would commit all of the crimes we now know he committed. The only way you could know that, apart from precognition, would be to have traveled backward in time from a point when Hitler had committed all his crimes and you knew about them.