Sacred Systems by Eric Kyle is tough going. He covers “systems” of personal transformation and spiritual formation from Philo through the Didache, Bonaventure, Erasmus and de Sales and William Law, to Dallas Willard.
Kyle is interested in the “system” that each advocates - their theology and cosmology, their theory of change, their ideals, the specific practices they advocate and emphasize, their modes of assessment and evaluation.
It’s a lot to cover, and Kyle’s complex diagrams didn’t do much to help this reader to sort it all out. Besides, it’s necessarily repetitive material. What Christian system of formation and transformation won’t emphasize constant prayer?
Fortunately, Kyle brings it all together in a final synthesis, summarizing each spiritual writer and classifying the different approaches in a variety of ways. He distinguishes, for instance, between systems that highlight habit and “embodying a way,” distinguishing these from systems emphasizing affective transformation or gnostic liberation and ascent. Some systems are more “intrapersonal,” others “interpersonal,” and the latter are such in different ways, depending on whether they emphasize rules or modeling and mimesis.
Theories of change vary from those that emphasize reason and other internal resources, those that highlight external formation, and those that emphasize God’s intervention. Writers differ on what is actually changing during the course of spiritual change: Is it an awakening of latent virtues or an overcoming of weakness?
I suggest reading this book back-to-front: Start with the final synthetic chapter, and then dip into Kyle’s detailed, nearly encyclopedic explications of the masters that he summarizes.