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 that 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 of totally immersing an infant underwater. However, Eastern Orthodox and some Roman Catholics practice infant immersion. Amish, Old Order Mennonites, and Conservative Mennonites still practice baptism by pouring.

Affusion became the standard practice in the western church around the 10th century, but was in use much earlier. The earliest explicit reference to baptism by affusion occurs in the Didache (c. AD 100), the seventh chapter of which gives instructions on how to baptize, which include affusion:

…But if you have no living water, baptize into other water; and if you cannot do so in cold water, do so in warm. But if you have neither, pour out water three times upon the head into the name of Father and Son and Holy Spirit (emphasis added)

This text implies that early Christians saw affusion is a viable alternative to immersion when no living water (i.e. running water like a river or spring) or cold water is available.

Acts of various martyrs show that many were baptized in prison, while awaiting martyrdom; immersion would have been impossible. The most common use, however, was for ill or dying people who could not rise from their beds. It was consequently known as "baptism of the sick." Receiving this baptism was regarded as a bar to Holy Orders, but this sprang from the person's having put off baptism until the last moment—a practice that in the fourth century became common, with people enrolling as catechumens but not being baptized for years or decades. While the practice was decried at the time, the intent of the criticism was not to encourage baptism by immersion, but to refrain from delaying baptism.

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