Logical fallacy #1: “Christians tortured "confessions" out of Jews.” The argument commits Appeal to Force fallacy. It makes no attempt to provide for the validity of the claim through any formal analysis, but asserts the righteousness of the claim by means of fire, scaffolds and swords. As cynical and cruel as it was, the oblivious masses were satisfied with the Jewish cries of desperation obtained under “Say it or Die now” condition. Obviously, the Medieval Do-Gooders religiously believed in the Exitus Acta Probat principle (lat. for “the outcome justifies the means.”) Interestingly enough, the majority of the Jews did not cooperate with those persecuting them by giving false self-incriminating testimonies but chose death instead. According to the Jewish Encyclopedia “… the Jews for the first time took active measures against their oppressors ... but finding the task of freeing themselves hopeless, they barricaded themselves in their dwellings, and when the alternative of starvation or baptism faced them, set fire to their houses and perished in the flames.”[http://www.jewishencyclopedia.com/view.jsp?artid=1114&letter=B]
Logical fallacy #2: “The Jews were believed to be "jealous" of the Christians (because, it was thought, the Jews knew "in their hearts" that they were damned).” This argument is a great example of the Appeal to Popularity logical fallacy. The mere fact of popularity of a certain idea does not prove or disprove of its validity (E.g. the geocentric system of universe of the Medieval ages.) In fact, jealousy does look to have played a key role in the issue but from the other end. In contrast to mostly Christian European peasants of the time, who were poor and illiterate, the Jews represented the class of urban bourgeois that engaged in the business of trading goods and money lending. The peasants seemed to have found a scapegoat for their misfortunes and been blinded by the jealousy for Jewish wealth and lifestyle set out on their crusade.