Since you have said that this also is impiously said by some men, that, inasmuch as we believe that God the Word was united to flesh, the Father also, inasmuch as he is named as being of the same nature, is necesarily said to have become incarnate, and the Holy Spirit also, we fitly say what we can and what we have believed, fixing our mind on the divine Scriptures, and not crying from the earth according to the prophet's saying , nor yet making up things that come from our heart . But this objection has occurred to them in this way. If so be that Christ cries in the gospel, «I am in my Father and my Father in me», and Paul again says that the Son is the image of the invisible God , and the Holy Spirit also the image of the Son, in that he said of those who had been admitted to the adoption as sons by the Spirit, «they became conformed to the image of his Son» , that it might be shown as following from this that the Holy Trinity is one essence , when it is said that the Son became incarnate, how can we not also allow that the Father and the Holy Spirit too became incarnate, inasmuch as they are in the Son and appear in him? This is what these say. But we say with intelligence: These, my good men, are the words of those who confuse the hypostases. But, if the Father is the Father, he never passes into the Son, and the Holy Spirit also remains fixedly and without transformation in his own hypostasis, and does not pass into the hypostasis of the Son: but the divine Scriptures have said that the Son became incarnate and became man, and it is on account of the co-essentiality that, the Father and the Holy Spirit are said to be in him, not in order that we may dissolve and confound the hypostasis of the Father and of the Holy Spirit in the Son. But, if the Son is the image of the Father, the very name 'image' shows that it is understood to be the image of another hypostasis separate from itself: for, if it is an image, it is an image of some one, and, because it is an unvarying image in all points, it is not therefore the person himself of whom it is an image; for, if it were the person himself, it would fail to . be an image, for of whom would it be an image? Suppose a man delineates and copies a design and pattern from an original tablet on to another, and draws it correctly in all points, and makes the copy like the original, in no point falling short of the pattern that was first designed, but makes the colour and form and stature and size and pose of the limbs also alike, and those who see it for the first time do not know, if one may so say, which is the original from which it was drawn and designed, on account of the exact resemblance of the appearance in both, and after this he takes the copy and fixes it on a wall, then will anyone of right understanding say that the original tablet has been fixed on the wall, because it is a copy of it and contains all that belongs to the original pattern? So we say that the Son became incarnate, the true image of the Father, who has by nature everything that belongs to his begetter, and we do not on this account hold that the Father became incarnate, who appears in his own special hypostasis or person. What has been said is intended as an indication of the subject, in order that the understanding may receive a defective and obscure example, because the whole force of the example does not follow in the footsteps of the truth, since here the image is without soul and immoveable, and is limited by the appearance of colours, but above there is a living and moveable image, suprasensual and unlimited and without appearance , and possessing immutability by nature. But, if we look into the divine Scriptures, we may through the mystery that has been richly revealed in them by another example also reçoive an illustration of what is stated. It is everywhere known that our speech is the offspring of our mind, and not the offspring only, but also the clear image, which represents the disposition that is in the depths of the mind, and with the speech comes forth also the breath of the mouth. The example is defective, and is a kind of similitude and shadow of the truth itself for those who are able to listen properly and intelligently. However, as our speech comes out through the organ of the voice and moves the hearing and passes inside him who hears, and no one says that the speech which is begotten by the mind, exists hypostatically, the speech which enters into the hearing of him who hears, or says that the breath which comes out in the speech through the voice exists in hypostasis , but only calls it a help to the hearing, so understand also with regard to the mystery of God the Word, because he himself alone hypostatically and ineffably and as he himself only knows came to dwell in the Virgin's womb and became incarnate from her, and neither the Father his begetter nor the Spirit which proceeds shared in this, but according to the saying of John, «The Word became flesh, and he was God, and was with God» , as one with another, because the hypostases exist severally. Since then these things are so, that question of theirs which arises from ignorance is superfluous and vain, a question that amounts to actual impiety. «If» (they say) «you say that the Trinity is one nature, and say that there is one nature of the incarnate Word, how are you not driven to saying that the whole Trinity became incarnate?» I am surprised at the cunning rusticity of those men, as shown by the way in which they display courage without consideration against the right opinion. We use the name 'nature' sometimes generally of 'essence' , and sometimes specifically signifying the hypostasis of a man. We term all mankind one nature, as in the text «Every nature of beasts and of birds and of things that are in the water is subjected and made subject to human nature» : and again we call a man 'nature', Paul for instance or Peter or James. Where we name all mankind one nature, we use the name 'nature' generically in place of 'essence': but, where we speak of one nature of Paul, we employ the name 'nature' in place of 'individual hypostasis'. So also, when we say that the Holy Trinity is one nature, as in the text, «In order that we may be sharers of the divine nature» , we use the name 'nature' in place of the general designation 'essence' . And to say that the Holy Trinity is one nature is the same as to say that it is one Godhead, as we are in fact accustomed to call all mankind one nature. But, when we say 'one incarnate nature of God the Word', we say 'nature' in place of an individual designation, and thereby we denote the one actual hypostasis of the Word, like that of Paul or Peter or any single man. Therefore also, when we say one nature which became incarnate', we do not say so absolutely, but we say 'one nature of the Word himself, and clearly denote that it is one hypostasis. But again let no one stain the divine nature that is raised above all things with anything lowly taken from the example of Paul and Peter. For, although they are of the same essence, they differ not only in hypostases, but also in power and operation, and stature and shape, and in the various kinds of impulses that are in men's minds. The Holy Trinity however differs by the difference of hypostases only, and in every point is unvarying in equality, and in the fact that it is of the same essence. And avoid that poverty of the example which is not worthy of the Godhead, and do not conceive of the Word as without hypostasis, nor yet of the Spirit as being dissipated in the air .