brightness of His glory, and
the figure of His substance." (Heb. 1:3).

Some explain this by the fact that the Son agrees with the Father, not
in nature only, but also in the notion of principle: whereas the Holy
Ghost agrees neither with the Son, nor with the Father in any notion.
This, however, does not seem to suffice. Because as it is not by
reason of the relations that we consider either equality or inequality
in God, as Augustine says (De Trin. v, 6), so neither (by reason
thereof do we consider) that similitude which is essential to image.
Hence others say that the Holy Ghost cannot be called the Image of the
Son, because there cannot be an image of an image; nor of the Father,
because again the image must be immediately related to that which it
is the image; and the Holy Ghost is related to the Father through the
Son; nor again is He the Image of the Father and the Son, because then
there would be one image of two; which is impossible. Hence it follows
that the Holy Ghost is in no way an Image. But this is no proof: for
the Father and the Son are one principle of the Holy Ghost, as we
shall explain further on (Q. 36, A. 4). Hence there is nothing
to prevent there being one Image of the Father and of the Son,
inasmuch as they are one; since even man is one image of the whole
Trinity.

Therefore we must explain the matter otherwise by saying that, as the
Holy Ghost, although by His procession He receives the nature of the
Father, as the Son also receives it, nevertheless is not said to be
"born"; so, although He receives the likeness of the Father, He is
not called the Image; because the Son proceeds as word, and it is
essential to word to be like species with that whence it proceeds;
whereas this does not essentially belong to love, although it may
belong to that love which is the Holy Ghost, inasmuch as He is the
divine love.

Reply Obj. 1: Damascene and the other Greek Doctors commonly employ
the term image as meaning a perfect similitude.

Reply Obj. 2: Although the Holy Ghost is like to the Father and the
Son, still it does not follow that He is the Image, as above
explained.

Reply Obj. 3: The image of a thing may be found in something in two
ways. In one way it is found in something of the same specific
nature; as the image of the king is found in his son. In another way
it is found in something of a different nature, as the king's image
on the coin. In the first sense the Son is the Image of the Fa