Noetic prayer designates, within the hesychast and Philokalic traditions, a mode of prayer that is not merely verbal or liturgical but is wholly interior, enacted by the nous — the spiritual intellect — operating within the heart. The Philokalia corpus, as translated by Palmer, Sherrard, and Ware, represents the primary documentary reservoir for this term in the depth-psychology library, with figures such as Gregory of Sinai, Evagrios the Solitary, Symeon the New Theologian, and Nikiphoros the Monk articulating its phenomenology across several centuries. Two central tensions animate the material. First, there is the question of mode and initiation: Gregory of Sinai identifies two distinct pathways by which noetic prayer is activated — the intellect cleaving directly to God prior to prayer, or prayer itself progressively quickening the intellect into union. Second, there is the matter of discernment, since the very interiority of noetic prayer renders it susceptible to demonic counterfeits and delusion, requiring careful navigation between authentic divine warmth and phantasmal light. John Climacus supplies the structural vocabulary, describing the hesychast as one who perpetually emits ‘noetic activity’ (noera ergasia). The tradition unanimously frames noetic prayer not as a human achievement but as the Spirit’s own energeia working through a purified vessel, making it a nexus between ascetic anthropology, theosis, and mystical epistemology.