Pseudo-Dionysius is the name given to an unknown Christian theologian and philosopher, probably a Syrian monk, who wrote around the year 500. He presented his works as those of Dionysius the Areopagite, Paul's Athenian convert, and they carried apostolic weight for a thousand years. His Mystical Theology founded the apophatic, or negative, way of speaking about God; our library also holds On the Divine Names and The Celestial Hierarchy.
Free: get it — here or in the Christian Classics app — and it's yours to read and listen to on every device you sign in to. About a tenth of it can be read here first, free.
The complete works attributed to Dionysius the Areopagite, the sixth-century Syrian writer who took the name of Paul's Athenian convert. They include The Celestial Hierarchy, The Divine Names, and The Mystical Theology, writings that shaped medieval teaching on angels, worship, and the soul's ascent to God. This is John Parker's English translation, published in 1897.