The Book of Privy Counseling is often packaged with The Cloud of Unknowing. This short work is written by the same author as The Cloud, and represents his mature thought, after years of giving himself to the spiritual work.
Chapter 1 of The Book of Privy Counseling could serve as a summation of the author's understanding of apophatic prayer.
"When you go apart to be alone for prayer, put from your mind everything you have been doing or plan to do. Reject all thoughts, be they good or be they evil. Do not pray with words unless you are really drawn to this; or if you do pray with words, pay no attention to whether they are many or few. Do not weigh them or their meaning. Do not be concerned about what kind of prayers you use, for it is unimportant whether or not they are official liturgical prayers, psalms hymns, or anthems; whether you formulate them interiorly by thoughts, or express them aloud, in words. See that nothing remains in your conscious mind save a naked intent stretching out toward God. Leave it stripped of every particular idea about God (what he is like in himself or in his works) and keep only the simple awareness that he is as he is. Let him be thus, I pray you, and force him not to be otherwise. Search into him no further, but rest in this faith as on solid ground. This awareness, stripped of ideas and deliberately bound and anchored in faith, shall leave your thought and affection in emptiness except for a naked thought and blind feeling of your own being. It will feel as if your whole desire cried out to God and said:
That which I am I offer to you, O Lord,
without looking to any quality of your
being but only to the fact that you
are as you are; this, and nothing more.
Let that quiet darkness be your whole mind and like a mirror to you. For I want your thought of self to be as naked and as simple as your thought of God, so that you may be spiritually united to him without any fragmentation and scattering of your mind. He is your being, and in him, you are what you are, not only because he is the cause and being of all that exists, but because he is your cause and the deep center of your being. Therefore, in this contemplative work think of your self and of him in the same way: that is, with the simple awareness that he is as he is, and that you are as you are. In this way your thought will not be fragmented or scattered but unified in him who is all.
Yet keep in mind this distinction between yourself and him: he is your being but you are not his. It is true that everything exists in him as in its source and ground of being, and that he exists in all things, as their cause and their being. Yet a radical distinction remains: he alone is his own cause and his own being. For as nothing can exist without him, so he cannot exist without himself. He is his own being and the being of everything else. Of him, alone may this be said; and thus he is wholly separate and distinct from every created thing. And thus, also, he is one in all things and all things are one in him. For I repeat: all things exist in him; he is the being of all.
And since this is so, let grace unite your thought and affection to him, while you strive to reject all minute inquiry into the particular qualities of your blind being or of his. Leave your thought quite naked, your affection uninvolved, and your self simply as you are, so that grace may touch and nourish you with the experimental knowledge of God as he really is. In this life, this experience will always remain dark and partial so that your longing desire for him will be ever newly enkindled."
– The Book of Privy Counseling, Chapter 1
This will be the last post in The Cloud of Unknowing series. Coming from a Christian background, this is one of the first books that led me down the contemplative path. I personally believe that this is one of the profound works of contemplative thought in world history and highly recommend getting a copy to dig into it further. See the Centering Prayer page for more on The Cloud of Unknowing and its relationship to the Centering Prayer movement.
To end this series, here is a lecture on The Cloud given by Father Dennis Billy from St. Charles Borromeo Seminary.