Apollinaris of Laodicea (d. 382) started out as a well-known opponent of Arianism. As time went on, his arguments for Christ’s full divinity fell into its own set of errors on at least three points.
First, Apollinaris oddly affirmed that Christ’s flesh in some sense descended from heaven, although it is not clear exactly what he means. He seems to want to show Christ’s divine origin, although the way he argues for it involves a teaching that rises eyebrows.
Second, Apollinaris affirmed so strongly the union of Christ’s divine and human nature that he spoke of him being one Incarnate nature. Probably, the idea of his bodily birth from Mary and descent from heaven—as noted above—aimed to show the unity of his divine and human natures. But it was awkward to say the least. Writers like Cyril of Alexandria would later affirm something similar to Apollinaris but with a much clearer emphases on how Christ came from two natures, without confusing or mixture. For Apollinaris, it is this mixture that precisely shows the full truth about Christ and his saving benefits.
Third, Apollinaris argued that the divinity and humanity of Christ mix together to unite into one Incarnate nature while keeping the properties of deity and humanity unconfused. Apollinaris wanted to avoid the idea that Christ was a chimera of divinity and humanity. Rather, he believed that Christ was a true human being: body and soul, out man and inner man.
Yet Apollinaris believed that Scripture taught our “inner man” included the mind (Greek nous). As Paul says in Romans 12, we renew our mind (nous); or in Romans 7, the mind (nous) is at war with the flesh. Given this biblical teaching, Apollinaris observed that the Bible calls God Spirit (e.g., John 4:24); it also calls Christ Spirit (1 Cor 15:45). In similar ways, Scripture calls God the Son Wisdom and Logos (reason). So, Apollinaris reasoned, when God the Son became human, he must be the reason or wisdom or mind (nous) of the human nature assumed. After all, if the humanity of Christ had a wisdom, reason, or nous, then God the Son would simply make the human wisdom wise by participation just like anyone else. But Christ is Wisdom, Logos, Spirit.
So imagining that a human is made up into one nature from at least three parts as Paul lists the parts of a human body, soul, spirit (1 Thess 5:23), Apollinaris reasons that the Logos is the spirit of man, mixed into his nature, to make Christ a full human—body, soul, and Spirt (Logos).
And it must be so, reasons Apollinaris, since how else can a human live sinless and sanctify human nature, body and soul, unless the divine Spirit does the work. Christ is one Person, after all; and two say there is a human Nous and a divine Nous in Christ seems to create conflict. This position today has some adherents, William Lane Craig for example, holding to a form of Apollinarianism.
On the basis of Scripture, weighty judgments by ancient Christians rejected Apollinaris’s view of Christ. To cite the famous words of Gregory of Nazianzus, “what is not assumed is not healed,” and so if Christ did not assume a human mind, then our minds—scorched by sin—remain unhealed of their malady. Further, as Gregory explains, Apollinaris makes Christ a mindless man, which Gregory thinks is better applied to the theology of Apollinaris—a mindless theology! Yes, early Christians were not above insults. But Gregory makes such a statement for an important theological reason: if Christ did not assume a human mind, we have sick minds. So it was not so much an insult as a theological judgment on the implications of Apollinaris’s views.
At the end of the day, the Bible speaks to clearly about Jesus’s full humanity to simply say Christ had no human mind. The Bible tells us he like us in every way except one: Christ was sinless (Heb 4:15; 1 Pet 2:22). Sinlessness is the mark of distinction. And so Gregory’s arguments, on the basis of Scripture, held more weight since it corresponded to biblical truth.
To ratify this judgment, the first canon of the Council of Constantinople (381) condemned Apollinarianism:
“The Faith of the Three Hundred and Eighteen Fathers assembled at Nice in Bithynia shall not be set aside, but shall remain firm. And every heresy shall be anathematized, particularly that of the Eunomians or [Anomæans, the Arians or] Eudoxians, and that of the Semi-Arians or Pneumatomachi, and that of the Sabellians, and that of the Marcellians, and that of the Photinians, and that of the Apollinarians.”
And so the teaching of Apollinaris was condemned because he made Christ into a partial human, one who could not wholly save us. His teaching contradicting holy Scripture, and so the fathers condemned it.