Symeon the New Theologian is known for his mysticism of divine light and his constant preoccupation with the theme of perfection. This chapter first examines this preoccupation, specifically his opposition to what is dubbed ‘the heresy of mediocrity’. In order to live up to the name, every Christian, for Symeon, must be oriented towards the fullness of perfection. This chapter highlights the unmistakably Christocentric form this perfection takes in Symeon, emphasizing in particular his tendency to transpose the language of Byzantine Christological dogma (Christ as one person in two natures, energies, and wills) into the arena of human perfection. The strong correlation between Symeon’s understanding of the incarnate Christ and his understanding of the human ideal towards which all must strive is the chief focus of this chapter.