The Holy Fathers studied “the historical description of the Fall, to which Holy Scripture refers”, but they interpreted those events through their own experience, as they knew what the illuminated nous was.
“The illumination of man means the indwelling of the Holy Spirit in his heart. Then he becomes a temple of the Holy Spirit and the Holy Spirit Himself acts within his nous and illumines it.”
“How do we know that Adam’s nous was darkened? Simply because we know that we ourselves now have a darkened nous.”The experience of the darkened and illuminated nous led the holy Fathers to interpret the state of Adam both before and after the Fall. It is essential to stress this to enable us to grasp that the holy Fathers were not speaking philosophically or imaginatively but empirically. After this explanation we should define what is meant by the inactivity and darkening of the nous, in other words, we need to investigate what is meant by the ‘inactive nous’. Man’s nous, as it was created by God, should have moved towards Him and have been characterised by ‘supranatural’ movement. With the Fall, however, it lost this movement and moves ‘naturally’ or ‘un- naturally.The faculty of the nous is ‘faulty’, and this finds expression in the fact that man becomes selfish, turns towards the body, and has selfish love instead of selfless love. “The nous exists in the fallen state and it is inactive. It has vestigial energy that needs to be activated.” When the nous “does not function correctly” it is called an inactive nous “For us the Fall is located in the nous, that is to say, when the nous stopped functioning. This the Fall.” Unnatural functioning of the nous means that it does not receive the energy of God’s Light, so it becomes dark.That is why we reii to the ‘darkening of the nous’, which is the most characteristic feature of the Fall. A darkened nous “means that the noetic faculty in man’s heart does not function correctly.” This is sin. “Sin is the darkening of the nous, the darkness in man’s heart.” All the Fathers spoke about the darkening of the nous.”
After the sin, death entered man’s existence, firstly spiritual death, the loss of God’s grace, and then physical death. Spiritual death is the darkening of the nous and the interruption of the relationship of the soul and nous with God. “God is not the cause of death. Man brought death on himself because he separated himself from the glory of God, Who is the source of his life. Consequently God did not impose death on man as a punishment for any sort of inherited guilt. Rather, God permitted death on account of His goodness and love, so that the sin and evil in man would not become immortal.”
Fr John Romanides : The fall of man. From Empirical Dogmatics Vol 2, page174.179.180