The "dark" in the title has to do (as the subtitle says) with the difficulty of prayer experiences.
The book talks about "intimacy", which Hassel gives his own flavor to.
This book seems idiosyncratic, which makes me think it partially comes out of the author's own life. This is interesting in itself.
Here are some notes I took, related to the book:
"Powerlessness" has its own meaning that Hassel gives it. An illustration he gives of it is how John the Baptist was in the desert for years, Mary went through all kinds of particular things after her "let it be so", and Jesus also, once his ministry began, was at the mercy of it. Something about how we live for years and years in particular parts of life we don't have much if any control over, and there's a prayer for this.
Intimacy in one area leads to intimacy in another.
I'm reading Hassel's Dark Intimacy right now. It has a good section on powerlessness. There's also a section on the "prayer of being". On pp. 95 - 96:Hassel identifies this fourth level as the inmost being. He notes on p. 101 that Jesus on the cross had joy on the fourth level while feeling complete affliction and desolation on the upper three. (Or maybe he had expectation of joy on the fourth level, that might be more in keeping with the source verse for "joy" on the cross, Hebrews 12:2.)
Let us glance at these levels of human experience so as to better understand dryness in prayer. There is, first, a superficial level which presents to our awareness pleasures and pains like the constant purr of an air-conditioner, the heavy perfume of lilacs, the irritation of a skin rash or a raspy voice, the comforting warmth of a May sun or an April shower. The first level, then, is a constant stream of sensate impressions, the context of life.
Underneath this is a second layer of deeper experiences, such as the constant ache of neuralgia or the deep pleasure of loving intercourse or the delight of solving a perplexing business problem or the lyric leap of an evening at the symphony or the exuberant planning for the first baby or the panic fear of a flashing knife. This second level is more meaningful and lends greater depth to the first one.
But underlying both of these is a still more profound set of experiences which make up the third level. It is at this level that one experiences the enervating worry at not having a job, the satisfaction of affectionate family living, the sorrow of watching the alcoholic spouse struggle for respectability, the fulfillment of a successfully completed project demanding ten years of one's life, the sense of wortwhileness in the costly sacrifice for the beloved. At this third level the deepest hopes are raised or dashed, the finest joys are brought into full bloom, and the most crushing sorrows test the stamina of a person's very being.
Believe it or not, there is yet a fourth level, which is the dynamic basis of the three upper levels of experience. Although the top three levels are directly knowable to oneself, this fourth level is discovered and known only indirectly, that is, only in contrast with the other three. Thus a woman can be in good health on the first level, can be enjoying a full family life on the second level, can see her role in life as richly meaningful on the third level, and yet be restless and pain-filled on the fourth level. If it were not for this dramatic contrast with the top three levels, she could not possibly come to know the fourth level as part of her experience.
I can't remember if Hassel says this early in the book or if I'm making this up (it took me a while to read, so the beginning of the book is relatively distant to me), but I possess the feeling that his "Prayer-Experiences" could be read as "experiences or places in life which are prayer". There's a quote from the Psalms that I like that says "In return for my love they accuse me, but I am prayer". Well, it says that in the ESV and not in other translations, but I think it's a plausible translation, maybe the best. And what am I if not my life? I think there can be a distinction between me and my life, but at the same time, me living my life is a big part of me, so I am prayer when I live my life of powerlessness. The whole place in life of powerlessness itself is communion with God.
The book had a discussion about bitterness that I also found helpful.
There were other parts I was less interested in, but for what's mentioned in this review, I can recommend this book.