Impeccability is the absence of sin. Christianity teaches this to be an attribute of God (logically God cannot sin: it would mean that he would act against his own will and nature) and therefore it is also attributed to Christ. Roman Catholic teaching Impeccability and Heaven Early Christians questioned whether the victorious saints in heaven could sin. The widely influential Eastern Church Father and theologian Origen of Alexandria maintained that they could. Official Roman Catholic doctrine holds that they cannot. Although Catholics believe in the gift of free will, saints in heaven already see God face to face and are incapable of sinning (see Pope Benedict XII and beatific vision), i.e., they will necessarily remain in God. The Catechism of the Catholic Church states (emphasis added): Impeccability and Purgatory The 13th-century, Dominican theologian Thomas Aquinas taught that souls in Purgatory cannot sin (Summa Theologica, Second Part of the Second Part, Question 83, Article 11, Reply to Objection 3), let alone the saints in heaven. This is the teaching of the Roman Catholic Church, although there are different opinions on the reasons for the impossibility to sin. Impeccability and the Virgin Mary The Roman Catholic Church teaches that Mary, mother of Jesus was, by a special grace of God, without sin her entire life. This included the moment of her conception, so Mary was even miraculously preserved from original sin and its effects. The Immaculate Conception is a Roman Catholic dogma that asserts that Mary was preserved by God from the stain of original sin at the time of her own conception. Some theologians have asserted this special grace extended to impeccability (understood in this context as the inability to sin); others argue this could not be so: as a natural human being, she would have had free will, and therefore the ability to sin, but through her co-operation avoided it. Protestant Christian theology holds that Jesus died for the sins of even his mother, who had at least two other sons, Jesus' brothers Jude and James. Impeccability and the Pope Impeccability is sometimes confused with infallibility, especially in discussions of papal infallibility. Impeccability is an attribute not claimed by the pope, and few would deny that there have been bad popes – Saint Peter himself denied Jesus three times. On the other hand, Pope Gregory VII, intellectual progenitor of the Ultramontanes and nemesis of the lay faction in the investiture