"'Logismoi are much more intense than simple thoughts. They penetrate into the very depths of a human being. They have enormous power. Let us say,' Fr. Maximos went on to clarify, 'that a simple thought is a weak logismos. We need to realize, however, that certain thoughts, or logismoi, once inside a human being, can undermine every trace of a spiritual life in its very foundation. People who live in the world don't know about the nature and power of logismoi. That is, they don't have the experience of that reality. But as they proceed on their spiritual struggle, particularly through systematic prayer, then are they able to understand the true meaning and power of this reality'" (118).
"'I have noticed that some people, particularly young, oversensitive souls,' Fr. Maximos said, breaking the silence, 'suffer so much from these logismoi that it often leads them into psychopathological conditions. They reach such states partly because of their ignorance of the nature of logismoi. Such persons who may be attacked by a perverted, or let us say a sinful logismos, are unable to realize that such a logismos does not necessarily emanate from within themselves, but is directed toward them from the outside. They feel guilty and begin what the late Paisios used to call the 'the repetition of those whys.' They become obsessive. Oversensitive persons become even more sensitive and blame themselves with all kinds of questions: "Why do I have such a thought, why?" Such people are in dire need of proper instruction on how to handle the logismoi,' Fr. Maximos pointed out. He went on to say that the most dangerous logismoi are those sent by demonic spirits that get support and get activated by our own passions. Logismoi coming from demons are extremely devious and duplicitous" (120).
For more on logismoi, including the stages of their development (assault, interaction, consent, captivity, and passion) and strategies for mastering them, see Chapter 9 on "Invisible Intruders" and Chapter 10 on "Strategies" in The Mountain of Silence.
Source: Markides, Kyriacos C. The Mountain of Silence: A Search for Orthodox Spirituality. New York, NY: Doubleday, 2001.