St. Sophrony, passing on the hesychastic teachings of his spiritual father, St. Silouan the Athonite, speaks of the superiority of the cardio-noetic state over the realm of fallen existence. Through neptic diakrisis (watchfulness and discernment), a person learns to reject all mental images, for each is linked to a particular kind of spirit that must be discerned without becoming entangled in it.
"The mind, having united with the heart, abides in such a state that it is able to perceive every movement occurring within the “sphere of the subconscious.” Abiding within the heart, the mind discerns the images and thoughts arising in its surroundings, coming from the sphere of cosmic being and attempting to seize the heart and mind of the person. In the form of a thought, that is, a mental activity connected to a particular image, is the energy of a particular spirit. The onslaught of thoughts coming from without is extremely strong, and to weaken it, the monk must, throughout the day, prevent even a single passionate glance, allow himself no attachment to anything. The monk constantly strives to reduce the number of external impressions to the absolute minimum; otherwise, at the moment of inner, intelligent prayer, everything imprinted upon him returns to the heart like an uncontrollable wall, producing great turmoil. The goal of the monk is to achieve continuous intelligent-heart attention; and when, after many years of this ascetic struggle–“the most difficult” of all struggles–the sense of the heart becomes refined, and the mind, through “much weeping,” gains the power to repel every assault of passionate thoughts, then the state of prayer becomes unceasing, and the awareness of God’s presence and action manifests with great strength and clarity. Such is the path of the ascetic monk, and such was the path of the Blessed Elder."
— St. Sophrony of Essex (Starets Silouan the Athonite)