14 . John Paul II, in Evangelium Vitae, tries to sidestep this distinction by appealing to philosophical and scientific arguments. These arguments fail, however, to the degree that they blur the traditional and phenomenological distinction between a potential and an actual human being. In the end, John Paul II resorts to probabilism: "The mere probability that a human person is involved would suffice to justify an absolutely clear prohibition of any intervention aimed at killing a human embryo" (sec. 60). If fertilized ova are sometimes discharged from the womb during the menstrual cycle, would this mean that John Paul II should advocate that women bring all their soiled sanitary napkins to their parish priest for the rites of Christian burial?