To apply to Almighty God the principle that what a voluntary agent wishes, cannot be known by a knowledge of his substance," lays one open to the objection that, at that rate, the divine volitions are something over and above the divine substance, contrary to B. I, Chapp. LXXV - LXXVII. I suppose St Thomas would reply that a perfect comprehension of God's substance would reveal His volitions.

Of God and His Creatures: 3.56