In the material world, a foot is one thing, a ladder is another and wings still another. In the interior world, however, feet, ladders, and wings are the affections of a good will, with them, we walk, we climb, and we fly.
(En. in ps. 38, 2)
God has to be searched and invoked in the secret of a rational soul, which is called the interior man.
(De magistro 1)
No one is able to reach God without flying over oneself.
(In Io. Ev. XX, 8)