cially to the
Person, since it is a personal property, as appears from what was
said in the First Part (Q. 32, A. 3; Q. 40, A. 2). Therefore there is
but one filiation in Christ.

_I answer that,_ opinions differ on this question. For some,
considering only the cause of filiation, which is nativity, put two
filiations in Christ, just as there are two nativities. _On the
contrary,_ others, considering only the subject of filiation, which
is the person or hypostasis, put only one filiation in Christ, just
as there is but one hypostasis or person. Because the unity or
plurality of a relation is considered in respect, not of its terms,
but of its cause or of its subject. For if it were considered in
respect of its terms, every man would of necessity have in himself
two filiations--one in reference to his father, and another in
reference to his mother. But if we consider the question aright, we
shall see that every man bears but one relation to both his father
and his mother, on account of the unity of the cause thereof. For man
is born by one birth of both father and mother: whence he bears but
one relation to both. The same is said of one master who teaches many
disciples the same doctrine, and of one lord who governs many
subjects by the same power. But if there be various causes
specifically diverse, it seems that in consequence the relations
differ in species: wherefore nothing hinders several such relations
being in the same subject. Thus if a man teach grammar to some and
logic to others, his teaching is of a different kind in one case and
in the other; and therefore one and the same man may have different
relations as the master of different disciples, or of the same
disciples in regard to diverse doctrines. Sometimes, however, it
happens that a man bears a relation to several in respect of various
causes, but of the same species: thus a father may have several sons
by several acts of generation. Wherefore the paternity cannot differ
specifically, since the acts of generation are specifically the same.
And because several forms of the same species cannot at the same time
be in the same subject, it is impossible for several paternities to
be in a man who is the father of several sons by natural generation.
But it would not be so were he the father of one son by natural
generation and of another by adoption.

Now, it is manifest that Christ was not born by one and the same
nativity, of the Father from eternity, and