The Fathers teach that with the Fall, the human nous became darkened. Adam’s nous became darkened. The Fathers are not concerned with Adam per se, but with Adam’s nous and with the sickness that followed from the darkening of his nous. The Fathers speak about a nous void of understanding. Throughout Patristic literature, the whole issue of the Fall centers on this darkening of the human nous.
But how do we know that man fell? Just from the historical description of the Fall in Holy Scripture? And what does ‘the Fall’ really mean? What does ‘Paradise’ mean? What was Paradise? There are two Patristic traditions on this subject, which are summarized by St. John of Damascus, who gives us both Patristic opinions without taking a position himself on this issue.
One tradition says that Adam’s nous in Paradise was illumined. The other tradition says that the condition of his nous was such that he could behold God continuously and that this is what paradise meant for Adam – to see the glory of God. Both the Alexandrian tradition and Cappadocian tradition (of St. Basil the Great) maintain that before the Fall, Adam beheld God with his nous, while the Antiochian tradition (of St. john Chrysostom) maintains that his nous was simply illumined.18
St. John of Damascus takes no position as to whether Adam’s nous was merely illumined before the Fall, or whether it was in a state where it could continuously behold God, that is, in a state of continuous theosis. Why does this Father of the Church not take a position? Because what interests him is to provide two explanations for the original state of the nous and how it became darkened. But how do we know that Adam’s nous became darkened? Very simply, because we know that we ourselves now have a darkened nous. And this darkened nous needs healing. The cure has two phases: illumination and theosis. Theosis is the complete cure.
But what does it mean to say that the nous has become darkened? It means that the noetic activity in the human heart is not functioning properly. Noetic energy begins to function properly only when man passes through purification and reaches illumination. After the Fall, the nous is in a darkened state. Why? Because it is full of thoughts (logismoi) and has been darkened by these thoughts. And when does the nous become darkened by thoughts? The nous is darkened when the thoughts of our reasoning mind [dianoia] descend into the heart and become thoughts of the nous, that is, when the location of our thoughts becomes confused between the rational mind and the nous. Thoughts are present in our nous that should not be there, because they belong to our reasoning faculty, the dianoia. The nous must be utterly empty of thoughts in order for it to remain pure and thus receptive, so that the Holy Spirit can come and dwell and remain in it.
—Protopresbyter John S. Romanides