Apollinaris had collaborated with his father Apollinaris the Elder in reproducing the Old Testament in the form of Homeric and Pindaric poetry, and the New Testament after the fashion of Platonic dialogues, when the emperor Julian had forbidden Christians to teach the classics.

He is best known, however, as a noted opponent of Arianism.

Teaching that human beings are composed of body, soul, and spirit, his eagerness to emphasize the deity of Jesus and the unity of his person has led him so far as to deny the existence of a rational human soul (νους, nous) in Christ's human nature, this being replaced in him by the logos, or the second person of the Trinity, so that his body was a glorified and spiritualized form of humanity.

Over against this the orthodox or Catholic position maintains that Christ assumed human nature in its entirety including the νους, for only so could He be example and redeemer.

It is alleged that the system of Apollinaris is really Docetism, that if the Godhood without constraint swayed the manhood there was no possibility of real human probation or of real advance in Christ's manhood.