intellect is twofold--when the
universal is abstracted from the particular, as animal abstracted from
man; and when the form is abstracted from the matter, as the form of a
circle is abstracted by the intellect from any sensible matter. The
difference between these two abstractions consists in the fact that in
the abstraction of the universal from the particular, that from which
the abstraction is made does not remain; for when the difference of
rationality is removed from man, the man no longer remains in the
intellect, but animal alone remains. But in the abstraction of the
form from the matter, both the form and the matter remain in the
intellect; as, for instance, if we abstract the form of a circle from
brass, there remains in our intellect separately the understanding
both of a circle, and of brass. Now, although there is no universal
nor particular in God, nor form and matter, in reality; nevertheless,
as regards the mode of signification there is a certain likeness of
these things in God; and thus Damascene says (De Fide Orth. iii, 6)
that "substance is common and hypostasis is particular." So, if we
speak of the abstraction of the universal from the particular, the
common universal essence remains in the intellect if the properties
are removed; but not the hypostasis of the Father, which is, as it
were, a particular.

But as regards the abstraction of the form from the matter, if the
non-personal properties are removed, then the idea of the hypostases
and persons remains; as, for instance, if the fact of the Father's
being unbegotten or spirating be mentally abstracted from the Father,
the Father's hypostasis or person remains.

If, however, the personal property be mentally abstracted, the idea of
the hypostasis no longer remains. For the personal properties are not
to be understood as added to the divine hypostases, as a form is added
to a pre-existing subject: but they carry with them their own
_supposita,_ inasmuch as they are themselves subsisting persons; thus
paternity is the Father Himself. For hypostasis signifies something
distinct in God, since hypostasis means an individual substance. So,
as relation distinguishes and constitutes the hypostases, as above
explained (A. 2), it follows that if the personal relations are
mentally abstracted, the hypostases no longer remain. Some, however,
think, as above noted, that the divine hypostases are not
distinguished by the relations, but only by origin; so