in things here below, unless He knew them, and exercised His
providence over them.

Reply Obj. 3: We have but one knowledge of the Father, Son, and Holy
Ghost, as to the unity of the Essence, to which the first article
refers: but, as to the distinction of the Persons, which is by the
relations of origin, knowledge of the Father does indeed, in a way,
include knowledge of the Son, for He would not be Father, had He not
a Son; the bond whereof being the Holy Ghost. From this point of
view, there was a sufficient motive for those who referred one
article to the three Persons. Since, however, with regard to each
Person, certain points have to be observed, about which some happen
to fall into error, looking at it in this way, we may distinguish
three articles about the three Persons. For Arius believed in the
omnipotence and eternity of the Father, but did not believe the Son
to be co-equal and consubstantial with the Father; hence the need for
an article about the Person of the Son in order to settle this point.
In like manner it was necessary to appoint a third article about the
Person of the Holy Ghost, against Macedonius. In the same way
Christ's conception and birth, just as the resurrection and life
everlasting, can from one point of view be united together in one
article, in so far as they are ordained to one end; while, from
another point of view, they can be distinct articles, in as much as
each one separately presents a special difficulty.

Reply Obj. 4: It belongs to the Son and Holy Ghost to be sent to
sanctify the creature; and about this several things have to be
believed. Hence it is that there are more articles about the Persons
of the Son and Holy Ghost than about the Person of the Father, Who is
never sent, as we stated in the First Part (Q. 43, A. 4).