Catholic urban legends are myths of history created in the fervor of anti-Catholic passions. Unfortunately, they long ago became part of our cultural framework and are accepted today as undeniable truths.
Though centuries old, Catholic urban legends usually crop up as rhetorical devices meant to undermine positions taken by the Church on current public issues. That’s why Catholics questioning the morality and ethics of embryonic stem cell research, for example, will suddenly have Galileo thrown in their face. Rather than argue the issue at hand, those opposed to the Church position dust off a non-historical legend from the trial of Galileo to make the case that the contemporary Church opposes any and all scientific advances.