4 Is it, however, our Lord Jesus Christ Himself— His whole self— who was seen, and held, and crucified? Is the whole very self that? It is the same, but not the whole, that which the Jews saw; this is not the whole Christ. And what is? “In the beginning was the Word.” In what beginning? “And the Word was with God.” And what word? “And the Word was God.” Was then perhaps this Word made by God? No. For “the same was in the beginning with God.” What then? Are the other things which God made not like the Word?
No: because “all things were made by Him, and without Him was not anything made.” In what manner were all things made by Him? Because “that which was made in Him was life;” and before it was made there was life. That which was made is not life; but in the art, that is, in the wisdom of God, before it was made, it was life. That which was made passes away; that which is in wisdom cannot pass away. There was life, therefore, in that which was made. And what sort of life, since the soul also is the life of the body?
Our body has its own life; and when it has lost it, the death of the body ensues. Was then the life such as this? No; but “the life was the light of men.” Was it the light of cattle? For this light is the light of men and of cattle. There is a certain light of men: let us see how far men differ from the cattle, and then we shall understand what is the light of men. Thou dost not differ from the cattle except in intellect; do not glory in anything besides. Do you presume upon your strength?
By the wild beasts you are surpassed. Upon your swiftness do you presume? By the flies you are surpassed. Upon your beauty do you presume? How great beauty is there in the feathers of a peacock! Wherein then are you better? In the image of God. Where is the image of God? In the mind, in the intellect. If then you are in this respect better than the cattle, that you have a mind by which you may understand what the cattle cannot understand; and therein a man, because better than the cattle; the light of men is the light of minds. The light of minds is above minds and surpasses all minds. This was that life by which all things were made.
Source: Tractates on the Gospel of John (New Advent)