I just found this old inteview on-line with Susan Howatch very interesting. A Novelist Looks at Faith and Fiction
Here’s a quote from it:
I think if mystics try to operate outside a church framework, they go over the top into gnosticism and cloud cuckoo-land. You need a framework to stop you from being dishonest. In the Starbridge books the mystics had to have spiritual directors to focus—otherwise how do you know if you have it spot on or not?

