In this article, we intend to bring a small contribution to the knowledge of the Desert Fathers. First, we emphasize the main aspects of the spiritual life in Late Egyptian monasticism. In this sense, we discuss the category of clean and unclean and how they function within the world of the desert. This binary dynamism is not to be understood solely in a sexual fashion. One can consider, for instance, clean and unclean, places, thoughts, practices, relationships, and so on. The dialectic of clean/unclean is akin to thinking of what pollutes and does not pollute. To understand the tension between these polarities helps us to get a better fix on a whole range of monastic tropes: asceticism, the logismoi, the struggle with the demon, the demand for flight from the world etc. The monastic universe is one of the privileged places where were first developed and then applied the rules governing the patristic culture of the body. The ascetics who isolated themselves in the desert of Egypt (the fourth century) represent a social group that is statistically negligible. But from the mentality point of view, the experience of this group fulfills a decisive function in Eastern Christianity.