On the Trinity

^41. Thus, though Christ was present in God with these infinite and eternal decrees, He has granted to us nothing more than a knowledge of the fact of His birth; in order that, just as an apprehension of the birth is the means which leads to faith in God, so also the knowledge of the eternity of His birth might avail to sustain piety; since neither reason nor experience allow us to speak of any but an eternal Son as proceeding from a Father Who is eternal.