In his June 29, 1943 encyclical, Mystici Corporis Christi, we read the following in § 110:
Venerable Brethren,
may the Virgin Mother of God hear the prayers of Our paternal heart - which are
yours also - and obtain for all a true love of the Church - she whose sinless
soul was filled with the divine spirit of Jesus Christ above all other created
souls
Commenting on this passage, William D.
Most noted that:
Pius XII does not
make clear at what point in Mary’s life her holiness surpassed the combined final
grace of all other creatures. A very large number of theologians favor the view
that even her initial grace surpassed the final grace of all
others combined. For Pius IX, in the Ineffabilis Deus, said that “from
the beginning” God loved her “more than all creatures” and filled her with all
graces more than all creatures. Probably he meant more than all combined, for
he says that no greater holiness under God can be thought of—but if the
combined holiness of all other creatures were greater, then we could easily
think of a sanctify greater than hers.
If her initial grace
did surpass the combined final grace of all then this dazzling holiness must
have gone still higher, for during her whole life Mary always acted with the
maximum generosity. (Her would was full of grace at the start, but her capacity
for grace could and did grow.) Since the growth of a soul is proportioned to
its generosity, its capital of grace at the time, and God’s generosity to it,
her growth is staggering to think of! (William G. Most, “The Queenship of Mary,”
in Stanley G. Mathews, ed., Queen of the Universe: An Anthology on the
Assumption and Queenship of Mary [Saint Meinrad, Ind.: Grail Publications, 1957],
176-86, here, 184 n. 14)
