Informant38

Internet Theology Resources: Spirituality Francis de Sales (1567-1622)
Introduction to the Devout Life. [518K].
Treatise on the Love of God. Currently requires the ability to view PNG files, since whole sections of the HTML version are missing.
Francois Fenelon (1651-1715) and Jeanne Marie Guyon (1647-1717), Spiritual Progress, or, Instructions in the Divine Life of the Soul. Includes his Spiritual Letters, her book A Short and Very Easy Method of Prayer, and other works.
Alan Godlas, Sufism (1997). Excellent concise description of Sufism, with links to other resources. Dr. Godlas teaches Islamic Studies at the University of Georgia.
Guigo II (d. 1193), Scala claustralium. The quintessential medieval exposition of lectio divina.
L'echelle du cloitre. 1922 French translation, at the official web site of the Carthusians.
Scala paradisi. In Latin.
http://www.csbsju.edu/library/internet/theospir.html
Jeanne Marie Guyon, The Autobiography of Madame Guyon.
Hildegard of Bingen (1098-1179). A brief biography.
Walter Hilton (d. 1396)
The Scale of Perfection. Hilton's most famous work.
The Scale (or Ladder) of Perfection. 1901 Benziger Brothers edition. This 1870 translation by Cressy uses modernized spelling, but otherwise an archaizing form of English.
The Scale of Perfection. In Middle English. Edited by Thomas H. Bestul. Each Book in its own file, with notes.
The Song of Angels. Short treatise by Hilton.
Treatise Written to a Devout Man.
Roland Horst, Hildegard von Bingen. Good collection of resources, in German and English.
Ignatius of Loyola, Spiritual Exercises (1522-1548)