5 He shall also judge those who describe Christ as [having become man] only in [human] opinion. For how can they imagine that they do themselves carry on a real discussion, when their Master was a mere imaginary being? Or how can they receive anything steadfast from Him, if He was a merely imagined being, and not a verity? And how can these men really be partaken of salvation, if He in whom they profess to believe, manifested Himself as a merely imaginary being? Everything, therefore, connected with these men is unreal, and nothing [possessed of the character of] truth; and, in these circumstances, it may be made a question whether (since, perchance, they themselves in like manner are not men, but mere dumb animals) they do not present, in most cases, simply a shadow of humanity.
Source: Adversus haereses (New Advent)