§4. The text John xvi. 15, shews clearly the essential relation of the Son to the Father.
As then the light from the Sun which illumines the world could never be supposed, by men of sound mind, to do so without the Sun, since the Suns light is united to the Sun by nature; and as, if the Light 442 were to say: I have received from the Sun the power of illumining all things, and of giving growth and strength to them by the heat that is in me, no one will be mad enough to think that the mention of the Sun is meant to separate him from what is his nature, namely the light; so piety would have us perceive that the Divine Essence of the Word is united by nature to His own Father. For the text before us will put our problem in the clearest possible light, seeing that the Saviour said, All things whatsoever the Father hath are Mine; which shews that He is ever with the Father. For whatsoever He hath shews that the Father wields the Lordship, while are Mine shews the inseparable union. It is necessary, then, that we should perceive that in the Father reside Everlastingness, Eternity, Immortality. Now these reside in Him not as adventitious attributes, but, as it were, in a well-spring they reside in Him, and in the Son. When then you wish to perceive what relates to the Son, learn what is in the Father, for this is what you must believe to be in the Son. If then the Father is a thing created or made, these qualities belong also to the Son. And if it is permissible to say of the Father there was once a time when He was not, or made of nothing, let these words be applied also to the Son. But if it is impious to ascribe these attributes to the Father, grant that it is impious also to ascribe them to the Son. For what belongs to the Father, belongs to the Son. For he that honoureth the Son, honoureth the Father that sent Him, and he that receiveth the Son, receiveth the Father with Him, because he that hath seen the Son hath seen the Father (Matt. 10:40, John 14:9). As then the Father is not a creature, so neither is the Son; and as it is not possible to say of Him there was a time when He was not, nor made of nothing, so it is not proper to say the like of the Son either. But rather, as the Fathers attributes are Everlastingness, Immortality, Eternity, and the being no creature, it follows that thus also we must think of the Son. For as it is written (Joh. v. 26), As the Father hath life in Himself, so gave He to the Son also to have life in Himself. But He uses the word gave in order to point to the Father who gives. As, again, life is in the Father, so also is it in the Son, so as to shew Him to be inseparable and everlasting. For this is why He speaks with exactness, whatsoever the Father hath, in order namely that by thus mentioning the Father He may avoid being thought to be the Father Himself. For He does not say I am the Father, but whatsoever the Father hath.
Cf. Orat. iii. 36.