One of Evagrius Ponticus' great bequests to theological posterity was his classification of the thoughts (logismoi) which assail ascetics. He works with eight thoughts, generally, arranged according to their interrelations and ways of besetting monks. In the Latin West, thanks especialy to John Cassian and Gregory the Great, the eight thoughts become seven and emerge ultimately as the "Seven Deadly Sins" of Medieval spirituality. In the East, however, while other writers like Mark the Monk crafted different schemas of thoughts and their operation, Evagrius' eight-thought system remains the most prominent. Two centuries after Evagrius' death, John, abbot of St. Catherine's Monastery on the Sinai Peninsula, penned what would become the East's most influential piece of spiritual direction: The Ladder of Divine Ascent. Scholars generally believe John to modify Evagrius' system in this work to a seven-thought one, which draws on but differs from Cassian's. This paper will argue, on the contrary, that John develops Evagrius' eight-thought system but significantly alters the order to reflect a genealogical rather than operational schema. In doing so, it will benefit our understanding not only of John's presentation of the spiritual life (which relies heavily on genealogical presentations of thoughts) but also of what literature he likely read and what use he made of the controversial heritage of Evagrian spirituality.