Whether the dove in which the Holy Ghost appeared was real?

Objections

Objection 1 : It would seem that the dove in which the Holy Ghost appeared was not real. For that seems to be a mere apparition which appears in its semblance. But it is stated (Lk. 3:22) that the "Holy Ghost descended in a bodily shape as a dove upon Him." Therefore it was not a real dove, but a semblance of a dove.
Objection 2 : Further, just as "Nature does nothing useless, so neither does God" (De Coelo i). Now since this dove came merely "in order to signify something and pass away," as Augustine says (De Trin. ii), a real dove would have been useless: because the semblance of a dove was sufficient for that purpose. Therefore it was not a real dove.
Objection 3 : Further, the properties of a thing lead us to a knowledge of that thing. If, therefore, this were a real dove, its properties would have signified the nature of the real animal, and not the effect of the Holy Ghost. Therefore it seems that it was not a real dove.