gnified.

Reply Obj. 3: The properties of the dove lead us to understand the
dove's nature and the effects of the Holy Ghost in the same way.
Because from the very fact that the dove has such properties, it
results that it signifies the Holy Ghost.
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EIGHTH ARTICLE [III, Q. 39, Art. 8]

Whether It Was Becoming, When Christ Was Baptized That the Father's
Voice Should Be Heard, Bearing Witness to the Son?

Objection 1: It would seem that it was unbecoming when Christ was
baptized for the Father's voice to be heard bearing witness to the
Son. For the Son and the Holy Ghost, according as they have appeared
visibly, are said to have been visibly sent. But it does not become
the Father to be sent, as Augustine makes it clear (De Trin. ii).
Neither, therefore, (does it become Him) to appear.

Obj. 2: Further, the voice gives expression to the word conceived in
the heart. But the Father is not the Word. Therefore He is
unfittingly manifested by a voice.

Obj. 3: Further, the Man-Christ did not begin to be Son of God at His
baptism, as some heretics have stated: but He was the Son of God from
the beginning of His conception. Therefore the Father's voice should
have proclaimed Christ's Godhead at His nativity rather than at His
baptism.

_On the contrary,_ It is written (Matt. 3:17): "Behold a voice from
heaven, saying: This is My beloved Son in whom I am well pleased."

_I answer that,_ As stated above (A. 5), that which is accomplished
in our baptism should be manifested in Christ's baptism, which was
the exemplar of ours. Now the baptism which the faithful receive is
hallowed by the invocation and the power of the Trinity; according to
Matt. 28:19: "Go ye and teach all nations, baptizing them in the name
of the Father, and of the Son, and of the Holy Ghost." Wherefore, as
Jerome says on Matt. 3:16, 17: "The mystery of the Trinity is shown
forth in Christ's baptism. Our Lord Himself is baptized in His human
nature; the Holy Ghost descended in the shape of a dove: the Father's
voice is heard bearing witness to the Son." Therefore it was becoming
that in that baptism the Father should be manifested by a voice.

Reply Obj. 1: The visible mission adds something to the apparition,
to wit, the authority of the sender. Therefore the Son and the Holy
Ghost who are from another, are said not only to appear, but also to
be sent visibly. But the Father, who is not from another, can appear
indeed, but can