This week's heresy is one of the most detailed of which we still have surviving documentation.
Apollinarianism (also known as Apollinarism) is a 4th century heresy that teaches Jesus could not have had a human mind, but rather that Jesus had a human body and “lower soul” (the seat of emotions), but a Divine mind. Apollinaris, for whom this heresy is named, taught that the two natures simply couldn’t coexist, and so the “lesser form” (His human nature) gave way to the “greater form” (His Divine nature). This, along with Eutychianism, is a form of Monophysitism, which errantly teaches Christ only had one nature. Some at the time considered this an overreaction in response to Arianism, whose teachings were that Christ was simply not divine in nature. Polemianism and Antidicomarianism are considered to be “sub-Apollinarianism” heresies. At the First Council of Constantinople in 381, the followers of this heresy were accused of attempting to create a “tertium quid” (a “third thing” that is neither God nor Man). Apollinaris also taught in the same vein as Tertullian that the souls of men were propagated by other souls as well as their bodies (also known as Traducianism).