Affusion

Affusion (la. affusio) is a method of baptism where water is poured on the head of the person being baptized. The word "affusion" comes from the Latin affusio, meaning "to pour on". Affusion is one of four methods of baptism used by Christians, which also include total submersion baptism, partial immersion baptism, and aspersion or sprinkling.

Christian denominations which baptize by affusion do not deny the legitimacy of baptizing by submersion or immersion; rather, they consider that affusion is a sufficient, if not necessarily preferable, method of baptism. Affusion and aspersion tend to be practiced by Christian denominations that also practice infant baptism. This may be due to the practical difficulties and dangers of drowning and hypothermia associated with totally immersing an infant in cold water. However, Eastern Orthodox and some Roman Catholics practice infant immersion (though because of their different theology of original sin and historically different beliefs about the eternal fate of infants who die before baptism, Eastern Orthodox usually delay baptism until the infant is at least 40 days old, which considerably lessens the dangers of immersion). Amish, Old Order Mennonites, and Conservative Mennonites still practice baptism by pouring.