This actually reminds me of a debate I got into with Fr. Hewko (before his ordination) at STAS. St. Thomas Aquinas actually argued that the dove was a real, actual dove. I disagreed with that and felt that He only took on the appearance of a dove (Latin word here is specie ... which derives from the word to see/look and can mean either one). I felt that this opinion of St. Thomas opened up a highly problematic can of worms. Did the Holy Ghost just animate an existing dove or create a new one for Him to inhabit? Was the dove dead or did the Holy Ghost "possess" an living dove? If both the existing dove was there and the Holy Ghost, was there some other mystery of Incarnation here? So after the Holy Ghost left the dove, did it cease to exist, did it drop dead? Unless it ceased to exist, we'd be in search of some priceless holy relic. In fact, unless it ceased to exist (if it was real at all), I'm sure Our Lord's disciples would have snatched it up to keep as a relic. I felt it led to so many logical problems that I disagree with St. Thomas here and said it was just in the form or appearance of a dove, not somehow in or united to an actual dove (with or without its own animal soul). In any case, Fr. Hewko was shocked and almost scandalized that I would disagree with St. Thomas. I pointed out that St. Thomas was not infallible and that this was clearly a point of speculative theology that people could have varying opinions about without harm to faith or running afoul (pun intended at this time) of Revelation or the Magisterium ... but he wasn't convinced.