"Now it must be born in mind that in the human soul, as in every creature, there is a double passive power: one in comparison with a natural agent; --the other in comparison with the first agent, which can reduce any creature to a higher act than a natural agent can reduce it, and this is usually called the obediential power of a creature."
-St. Thomas Aquinas, IIIa, q. 11, a. 1.
"...nature, while not aspiring to the supernatural by its own forces, is capable of reaching the supernatural through the influence and operation of another, higher nature. This is obediential potency, which is actuated under the guidance of a higher being to which unreserved obedience is given."
-Matthias Scheeben in Nature and Grace.