Pseudo-Dionysius the Areopagite

Pseudo-Dionysius the Areopagite was an anonymous 5th/6th-century Christian theologian whose works—The Divine Names, The Mystical Theology, The Celestial Hierarchy—synthesized Neoplatonism with Christian theology, creating the foundational texts of Western mysticism and apophatic (negative) theology.

Founded the apophatic theological tradition; The Mystical Theology is the foundational text of Christian mysticism; The Celestial Hierarchy created the canonical angelology.