On the Christian Faith (De fide)

⁶³ If, then, the Son can, by virtue of a common hidden power of the same nature which He has with the Father, both see and act in an invisible manner, and by the fullness of His Godhead execute every decree of His Will, what remains for us but to believe that the Son, by reason of indivisible unity of power, does nothing, save what He has seen the Father doing, forasmuch as because of His incomparable love the Son does nothing of Himself, since He wills nothing that is against His Father's Will? Which truly is the proof not of weakness but of unity.